ALBERT

Description:    In the present study, a high Mn twinning induced plasticity (TWIP) steel and two Al-added TWIP steels were fabricated, and their microstructures, tensile properties, and cup formability were analyzed to investigate the effects of Al addition on deformation mechanisms in tensile and cup forming tests. In the high Mn steel, the twin formation was activated to increase the strain hardening rate and ultimate tensile strength, which needed the high punch load during the cup forming test. In the Al-added TWIP steels, the twin formation was reduced, while the slip activation increased, thereby leading to the decrease in strain hardening rate and ultimate tensile strength. As twins and slips were homogeneously formed during the tensile or cup forming test, the punch load required for the cup forming and residual stresses were relatively low, and the tensile ductility was sufficiently high even after the cup forming test. This indicated that making use of twins and slips simultaneously in TWIP steels by the Al addition was an effective way to improve overall properties including cup formability. Content Type Journal Article Pages 1-14 DOI 10.1007/s11661-011-1007-2 Authors Seokmin Hong, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Republic of Korea Sang Yong Shin, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Republic of Korea Hyoung Seop Kim, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Republic of Korea Sunghak Lee, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Republic of Korea Sung-Kyu Kim, Automotive Steels Research Group, Technical Laboratories, POSCO, Gwangyang, 545-711 Republic of Korea Kwang-Geun Chin, Automotive Steels Research Group, Technical Laboratories, POSCO, Gwangyang, 545-711 Republic of Korea Nack J. Kim, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Republic of Korea Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Hot-rolled, binary Mg-Nd alloys with compositions ≥0.095 at. pct undergo the texture weakening phenomenon that has been reported in a number of Mg–rare earth (RE) alloys. However, alloys with compositions ≤0.01 at. pct retain a strong basal texture typical of pure Mg and other Mg alloys. Measurements of intragranular misorientation axes obtained using electron backscatter diffraction (EBSD) show that more dilute alloys contain predominantly basal $$ 〈 a 〉 $$ dislocations, while richer alloys contain primarily prismatic $$ 〈 a 〉 $$ dislocations. It is suggested that this change in dislocation content is related to a change in the dynamic recrystallization (DRX) mechanism. Metastable second-phase Mg x Nd 1– x intermetallic particles are present within the alloys, and an annealing study indicates that the alloys undergoing texture weakening have grain sizes well predicted by classical Zener drag theory. Even though the more dilute alloys also contain second-phase particles, they are not sufficient to induce pinning. The promotion of nonbasal slip and the reduction in grain boundary mobility due to Zener drag are suggested as controlling mechanisms that promote the observed texture weakening phenomena. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-011-1018-z Authors Jason P. Hadorn, Materials Science and Engineering Department, University of Virginia, Charlottesville, VA 22904-4745, USA Kerstin Hantzsche, Magnesium Innovation Center (MagIC), Helmholtz Centre Geesthacht, 21502 Geesthacht, Germany Sangbong Yi, Magnesium Innovation Center (MagIC), Helmholtz Centre Geesthacht, 21502 Geesthacht, Germany Jan Bohlen, Magnesium Innovation Center (MagIC), Helmholtz Centre Geesthacht, 21502 Geesthacht, Germany Dietmar Letzig, Magnesium Innovation Center (MagIC), Helmholtz Centre Geesthacht, 21502 Geesthacht, Germany Sean R. Agnew, Materials Science and Engineering Department, University of Virginia, Charlottesville, VA 22904-4745, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Welding between AZ31B Mg alloy and Q235 mild steel was examined in this study. The effects of welding parameters were first investigated on the penetration depth into the steel and the shear strength of the joints. The optimum parameters and the maximum shear strength were obtained. Based on these parameters, alloying elements in the form of interlayers were added into the joints, and the shear strength was improved as high as 98 pct of the AZ31B Mg alloy. Microstructures of the joints were inspected with a scanning electron microscope and an electron probe micro-analyzer. Two bonding modes were proposed, and their effects on the joint shear strength were discussed. It is suggested that the bonding changed from nonmetallurgical to “semimetallurgical” mode with the addition of the interlayers, which contributed to the enhancement of the shear strength. Micro-hardness profiles were measured in the fusion zone of the joints, and their influence on the joint strength was also discussed. Intermediate phases that distributed uniformly in the fusion zone strengthened the microstructures, and thus, the shear strength was elevated. An empirical trend for Cu and Ni interlayer selection was proposed. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-011-1071-7 Authors Liming Liu, Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024 P.R. China Xiaodong Qi, Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024 P.R. China Zhaodong Zhang, Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian, 116024 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    First-principles method was performed to predict the effect of Ti addition on thickness and adhesion of 55 pct Al-Zn-1.6 pct Si coating. The results of optimized geometric configurations, total energy, and charge distributions for the Ti substitution in Fe2Al5 and FeAl3 phases indicated Ti will grab electronic charges from Al atoms, form bonds with neighboring Al, which will reduce the growth of Fe-Al intermetallic layers, and finally enhance the adhesion of the coating/substrate. Furthermore, experiments were performed to validate the prediction results of first-principles successfully. Content Type Journal Article Pages 1-6 DOI 10.1007/s11661-011-1037-9 Authors Guangxin Wu, School of Materials Science and Technology, Shanghai University, Shanghai, 200072 P.R. China Jieyu Zhang, School of Materials Science and Technology, Shanghai University, Shanghai, 200072 P.R. China Yuling Ren, Cold Rolling Plant, Baosteel Branch, Baoshan Iron & Steel Co. Ltd., Shanghai, 200941 P.R. China Guoyang Li, Cold Rolling Plant, Baosteel Branch, Baoshan Iron & Steel Co. Ltd., Shanghai, 200941 P.R. China Xiaochun Wu, School of Materials Science and Technology, Shanghai University, Shanghai, 200072 P.R. China Qian Li, School of Materials Science and Technology, Shanghai University, Shanghai, 200072 P.R. China Kuochih Chou, School of Materials Science and Technology, Shanghai University, Shanghai, 200072 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Quick preheating treatment of the Al-Ti-C pellets and high-intensity ultrasonic vibration are introduced in the fabrication of in-situ TiC p /Mg composites. Al-Ti-C pellets are preheated for about 130 seconds in the furnace at 1023 K (750 °C), in which magnesium is melted as well. In this process, plenty of heat can be accumulated due to the reactive diffusion between liquid aluminum and solid titanium in Al-Ti-C, and a small amount of Al 3 Ti phase is formed as well. After adding the preheated Al-Ti-C into the molten magnesium, thermal explosion takes place in a few seconds. In the meantime, high-intensity ultrasonic vibration is applied into the melt to disperse in-situ formed TiC particles into the matrix and degas the melt as well. Microstructural characterization indicates that in-situ formed TiC particles are spherical in morphology and smaller than 2  μ m in size. Furthermore, a homogeneous microstructure with low porosity of the magnesium composite is obtained due to the effect of ultrasonic vibration. A novel approach using the quick preheating treatment technique and high-intensity ultrasonic vibration to synthesize in-situ TiC p /Mg composites is proposed in our research. Content Type Journal Article Pages 1-9 DOI 10.1007/s11661-011-1041-0 Authors Z. W. Liu, School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240 P.R. China M. Rakita, Department of Mechanical Engineering Technology, Purdue University, West Lafayette, IN 47906, USA Q. Han, Department of Mechanical Engineering Technology, Purdue University, West Lafayette, IN 47906, USA J. G. Li, School of Materials Science and Engineering, Shanghai Jiaotong University, Shanghai, 200240 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Mg-10Gd-3Y-0.5Zr (wt pct) casting was subjected to friction stir processing (FSP) at a constant rotation rate of 800 rpm and varied travel speeds of 25, 50, and 100 mm/minute. FSP resulted in the generation of fine-grained microstructure and fundamental dissolution of coarse Mg 5 (Gd,Y) phase at the grain boundaries, thereby enhancing the tensile properties significantly at both room and elevated temperatures. The grain size of the FSP samples decreased with the increasing travel speed, whereas the microstructure heterogeneity with the banded structure (onion rings) became evident at a higher travel speed. Tensile elongation of the FSP samples increased as the travel speed increased, whereas the highest strengths were obtained at the medium travel speed of 50 mm/minute. Higher strengths and greater elongations were observed for the FSP samples in the transverse direction (TD) than in the longitudinal direction (LD). After post-FSP aging, the strengths of the FSP samples were increased significantly with the TD and LD exhibiting the same strengths; however, the elongation was decreased remarkably with the TD having higher elongation than the LD. A variation of the tensile properties was discussed in detail based on the microstructure heterogeneity and fracture surfaces. Content Type Journal Article Pages 1-16 DOI 10.1007/s11661-011-1076-2 Authors Q. Yang, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 P.R. China B. L. Xiao, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 P.R. China Z. Y. Ma, Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 110016 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The jerky and smooth flow curves in high-manganese twinning induced plasticity (TWIP) steels were investigated by comparing Fe-Mn-C and Fe-Mn-Al-C systems. The pronounced serrations on the flow curves of Fe-Mn-C TWIP steel, produced during tensile testing at 300 K (27 °C) and 373 K (100 °C), were shown to be the result of localized high-temperature Portevin Le-Chatelier (PLC) bands moving across the gage length throughout the deformation. The speed of the PLC bands and their temperature effects were found to be strongly dependent on the applied strain rate, which was controlled by adjusting the cross-head speed of the tensile testing machine. The localized temperature-dependent stacking fault energy (SFE) variations resulting from the PLC effect and adiabatic heating were analyzed and compared for both slow and fast deformation rates. The instabilities in the measured logarithmic strain values caused by jerky flow could cause the local strain rate to deviate systematically from the targeted (applied) strain rate. These instabilities are better observed by calculating the instantaneous strain rate (ISR) values for each instant of deformation along the entire gage length. Finally, a new type of diagram was developed by plotting the true stress against the ISR values. From the diagram, the onset of different mechanisms, such as deformation twinning, nonpronounced, and pronounced serrations, could be marked precisely. Content Type Journal Article Pages 1-19 DOI 10.1007/s11661-011-1070-8 Authors A. Saeed-Akbari, Department of Ferrous Metallurgy, RWTH Aachen University, 52072 Aachen, Germany A. K. Mishra, Department of Metallurgical & Materials Engineering, Indian Institute of Technology, Kharagpur, 721302 India J. Mayer, Central Facility for Electron Microscopy, Aachen, Germany W. Bleck, Department of Ferrous Metallurgy, RWTH Aachen University, 52072 Aachen, Germany Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The effect of preoxidation on the thermal shock of air plasma sprayed thermal barrier coatings (TBCs) was completely investigated in a combustion gas environment by burning jet fuel with high speed air. Results show that with increasing cycles, the as-oxidized TBCs lost more weight and enlarged larger spallation area than the as-sprayed ones. Thermally grown oxide (TGO) growth and thermal mismatch stress were proven to play critical roles on the as-oxidized TBC failure. Two types of significant cracks were identified: the type I crack was vertical to the TGO interface and the type II crack was parallel to the TGO interface. The former accelerated the TGO growth to develop the latter as long as the oxidizing gas continuously diffused inward and then oxidized the more bond coat (BC). The preoxidation treatment directly increased the TGO thickness, formed the parallel cracks earlier in the TGO during the thermal shocks, and eventually resulted in the worse thermal shock resistance. Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-011-1055-7 Authors Hui Mei, National Key Laboratory of Thermostructure Composite Materials, School of Materials Science, Northwestern Polytechnical University, Xi’an, Shaanxi 710072, P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The sublimation of glycyl-L-α-alanine (Gly-Ala), L-α-alanyl-L-α-alanine (Ala-Ala), and DL-α-alanyl-DL-α-valine (Ala-Val) aliphatic dipeptides is studied by electron ionization mass spectrometry in combination with Knudsen effusion. The temperature range in which substances sublime as monomer molecular forms is determined. Enthalpies of sublimation Δ s H °( T ) are determined for Gly-Ala, Ala-Ala, and Ala-Val. It is shown that the enthalpy of sublimation of dipeptides increases with an increase in the side hydrocarbon radical. The unknown Δ s H °(298) values for 17 amino acids and nine dipeptides are estimated using the proposed “structure-property” correlation model, in which the geometry and electron characteristics of molecules are used as structural descriptors. Content Type Journal Article Category Physical Chemistry of Surface Phenomena Pages 457-462 DOI 10.1134/S0036024412030065 Authors V. G. Badelin, Institute of Chemistry of Solutions, Russian Academy of Sciences, Ivanovo, 153045 Russia E. Yu. Tyunina, Ivanovo State University of Chemical Technology, Ivanovo, 153000 Russia A. V. Krasnov, Ivanovo State University of Chemical Technology, Ivanovo, 153000 Russia V. V. Tyunina, Ivanovo State University of Chemical Technology, Ivanovo, 153000 Russia N. I. Giricheva, Ivanovo State University, Ivanovo, 153025 Russia A. V. Girichev, Ivanovo State University of Chemical Technology, Ivanovo, 153000 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 3

Description:    The acid-base properties of metal acetylacetonates and chromatographic sorbents on the basis of Chromaton N with deposited combined stationary phases from polyethylene glycol (PEG 20M) and nickel(II) and iron(III) acetylacetonates have been investigated by means of pH measurement and Hammett indicator adsorption. The change of the acid-base state of the surface of Chromaton N depending on the nature of a metal of the modifying additive, the complex structure, and the deposition method has been demonstrated. Content Type Journal Article Category Physical Chemistry of Surface Phenomena Pages 463-467 DOI 10.1134/S0036024412030272 Authors Yu. G. Slizhov, Tomsk State University, Tomsk, 634050 Russia T. N. Matveev, Tomsk State University, Tomsk, 634050 Russia T. S. Minakova, Tomsk State University, Tomsk, 634050 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 3

Description:    The properties of the porous polymer Dowex L-285, modified by 5-hydroxy-6-methyluracil, are investigated by means of gas chromatography. It is found that the modification leads to a considerable increase in the sorption activity of the porous polymer with respect to both polar and nonpolar molecules. It is shown that each type of cavities in the supramolecular structure of 5-hydroxy-6-methyluracil contributes to the adsorption and thermodynamic properties of the modified adsorbent. Content Type Journal Article Category Physical Chemistry of Separation Processes: Chromatography Pages 475-478 DOI 10.1134/S0036024412030132 Authors V. Yu. Gus’kov, Bashkir State University, Ufa, 450074 Russia S. P. Ivanov, Institute of Organic Chemistry, Ufa Scientific Center, Russian Academy of Sciences, Ufa, 450054 Russia R. A. Khabibullina, Bashkir State University, Ufa, 450074 Russia R. R. Garafutdinov, Institute of Biochemistry and Genetics, Ufa Scientific Center, Russian Academy of Sciences, Ufa, 450054 Russia F. Kh. Kudasheva, Bashkir State University, Ufa, 450074 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 3

Description:    In this research a new idea for prediction of ultimate sizes of bimetallic nanocomposites synthesized in water-in-oil microemulsion system is proposed. In this method, by modifying Tabor Winterton approximation equation, an effective Hamaker constant was introduced. This effective Hamaker constant was applied in the van der Waals attractive interaction energy. The obtained effective van der Waals interaction energy was used as attractive contribution in the total interaction energy. The modified interaction energy was applied successfully to predict some bimetallic nanoparticles, at different mass fraction, synthesized in microemulsion system of dioctyl sodium sulfosuccinate (AOT)/isooctane. Content Type Journal Article Category Physical Chemistry of Nanoclusters and Nanomaterials Pages 2014-2017 DOI 10.1134/S003602441213002X Authors Alireza Salabat, Department of Chemistry, Faculty of Science, Arak University, P. O. Box 38156-8-8349, Arak, Iran Hassan Saydi, Department of Chemistry, Faculty of Science, Arak University, P. O. Box 38156-8-8349, Arak, Iran Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    Densities, viscosities, refractive indices and ultrasonic velocities of the binary mixtures of acetophenone with ethyl acetate were measured over the entire mole fractions at 303.15, 313.15, and 323.15 K. From the experimental results, excess molar volumes V E , viscosity deviation Δ η , refractive index deviation Δ n D , deviations in isentropic compressibility Δκ s and excess intermolecular free length Δ L f are calculated. The viscosity values were fitted to the models of Krishnan-Laddha and McAllister. The thermophysical properties under study were fit to the Jouyban-Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. The data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution. Content Type Journal Article Category Physical Chemistry of Solutions Pages 1947-1952 DOI 10.1134/S0036024412130195 Authors K. Saravanakumar, Department of Chemical Engineering, Sathyabama University, Chennai, 600119 India R. Baskaran, Department of Chemical Engineering, St. Joseph’s College of Engineering, Chennai-119, India T. R. Kubendran, Department of Chemical Engineering, A.C. College of Technology, Anna University, Chennai, 600025 India Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    The solubilities in the KCl-MgCl 2 -H 2 O system were determined at 50 and 75°C and the phase diagrams and the diagram of refractive index vs composition were plotted. Two invariant point, three univariant curves, and three crystallization zones, corresponding to potassium chloride, hexahydrate (MgCl 2 · 6H 2 O) and double salt (KCl · MgCl 2 · 6H 2 O) showed up in the phase diagrams of the ternary system, The mixing parameters θ K, Ca and Ψ K, Ca, Cl and equilibrium constant K sp were evaluated in KCl-MgCl 2 -H 2 O system by least-squares optimization procedure, in which the single-salt Pitzer parameters of KCl and MgCl 2 β (0) , β (1) , β (2) , and C ϕ were directly calculated from the literature. The results obtained were in good agreement with the experimental data. Content Type Journal Article Category Physical Chemistry of Solutions Pages 1930-1935 DOI 10.1134/S0036024412130146 Authors Ji-min Yang, School of Chemistry & Resources and Environment, Linyi University, Linyi, 276005 China Jing Peng, School of Chemistry & Resources and Environment, Linyi University, Linyi, 276005 China Yu-xia Duan, School of Chemistry & Resources and Environment, Linyi University, Linyi, 276005 China Chong Tian, School of Chemistry & Resources and Environment, Linyi University, Linyi, 276005 China Mei Ping, Experimental Centre, Linyi University, Linyi, 276005 China Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    The insertion reactions of the germylenoid H 2 GeClMgCl with RH (R = F, OH, NH 2 ) have been studied by using the DFT B3LYP and QCISD methods. The geometries of the stationary points on the potential energy surfaces of the reactions were optimized at the B3LYP/6-311+G( d , p ) level of theory. The calculated results indicate that all the mechanisms of the three insertion reactions are identical to each other. The QCISD/6-311++G( d , p )//B3LYP/6-311+G( d , p ) calculated potential energy barriers for the three insertion reactions of R = F, OH, and NH 2 are 164.62, 193.30, and 200.73 kJ mol −1 , and the reaction energies for the three reactions are −57.46, −35.65, and −22.22 kJ mol −1 , respectively. Under the same situation, the insertion reactions should occur easily in the following order H-F 〉 H-OH 〉 H-NH 2 . In THF solvent the insertion reactions get more difficult than in gas phase. Content Type Journal Article Category Structure of Matter and Quantum Chemistry Pages 1969-1973 DOI 10.1134/S0036024412130225 Authors Wen-Zuo Li, College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005 P. R. China Yu-Wei Pei, College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005 P. R. China Jian-Bo Cheng, College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005 P. R. China Qing-Zhong Li, College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005 P. R. China Bao-An Gong, College of Chemistry and Chemical Engineering, Yantai University, Yantai, 264005 P. R. China Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    The gas-phase reaction of palladium atom with acetone is investigated using density functional theory. Geometries and energies of the reactants, intermediates, and products involved are calculated. Both ground and excited state potential energy surfaces are investigated in detail. The present results show that the title reaction start with the formation of an η 2 -CH 3 COCH 3 -metal complex, followed by C-O, C-H, and C-C activation. These reactions can lead to four different products (PdO + C 3 H 6 , PdCH 2 COCH 3 + H, PdCH 2 + CH 3 CHO, and PdCOCH 2 + CH 4 ). The present results may be helpful in understanding the mechanism of the title reaction and further experimental investigation of the reaction. Content Type Journal Article Category Structure of Matter and Quantum Chemistry Pages 1982-1990 DOI 10.1134/S0036024412130092 Authors Guo-Liang Dai, School of Pharmaceutical and Chemical Engineering, Taizhou University, Linhai, 317000 China Chuan-Feng Wang, School of Pharmaceutical and Chemical Engineering, Taizhou University, Linhai, 317000 China Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    In this paper, biomimetic synthesis of calcium carbonate (CaCO 3 ) in the presence of biomolecules of two vegetables-tomato and capsicum is investigated. Scanning electron microscopy and X-ray powder diffractometry were used to characterize the CaCO 3 obtained. The biomolecules in the extracts of two vegetables are determined by UV-vis or FTIR. The results indicate that a mixture of calcite and vaterite spheres constructed from small particles is produced with the extract of tomato, while aragonite rods or ellipsoids are formed in the presence of extract of capsicum. The possible formation mechanism of the CaCO 3 crystals with tomato biomolecules can be interpreted by particle-aggregation based non-classical crystallization laws. The proteins and/or other biomolecules in tomato and capsicum may control the formation of vaterite and aragonite crystals by adsorbing onto facets of them. Content Type Journal Article Category Biophysical Chemistry Pages 2071-2075 DOI 10.1134/S003602441213016X Authors Long Chen, Department of Chemistry, Huangshan University, Huangshan, 245041 P. R. China Wang-Hua Xu, School of Chemistry and Chemical Engineering, Anqing Teachers College, Anqing, 246011 P. R. China Ying-Guo Zhao, School of Chemistry and Chemical Engineering, Anqing Teachers College, Anqing, 246011 P. R. China Yan Kang, Department of Chemistry, Huangshan University, Huangshan, 245041 P. R. China Shao-Hua Liu, Department of Chemistry, Huangshan University, Huangshan, 245041 P. R. China Zai-Yong Zhang, Department of Chemistry, Huangshan University, Huangshan, 245041 P. R. China Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    The Er 3+ :Y 3 Al 5 O 12 , an upconversion luminescence agent, which is able to transform the visible light to ultraviolet light, was synthesized by nitrate-citric acid method. And then, a novel photocatalyst, Er 3+ :Y 3 Al 5 O 12 /ZnO composites, was prepared by ultrasonic dispersing and liquid boil method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the structural morphology and surface properties of the Er 3+ :Y 3 Al 5 O 12 /ZnO. Azo Fuchsine dye was selected as target organic pollutant to inspect the photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /ZnO. The key parameters affecting the photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /ZnO, such as Er 3+ :Y 3 Al 5 O 12 content, heat-treatment temperature and heat-treatment time, were studied. In addition, the effects of dye initial concentration, Er 3+ :Y 3 Al 5 O 12 /ZnO amount and solar light irradiation time were also reviewed, as well as the photocatalytic activity in degradation of other organic dyes were compared. It was found that the photocatalytic activity of Er 3+ :Y 3 Al 5 O 12 /ZnO was much superior to pure ZnO under the same conditions. Thus, the Er 3+ :Y 3 Al 5 O 12 /ZnO is a useful photocatalyst for the wastewater treatment because it can efficiently utilize solar light by converting visible light into ultraviolet light. Content Type Journal Article Category Photochemistry and Magnetochemistry Pages 2049-2056 DOI 10.1134/S0036024412130262 Authors L. N. Yin, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China Y. Li, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China J. Wang, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China Y. M. Kong, College of Pharmacy, Liaoning University, Shenyang, 110036 P. R. China Y. Zhai, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China B. X. Wang, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China K. Li, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China X. D. Zhang, College of Chemistry, Liaoning University, Shenyang, 110036 P. R. China Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    In this work, we report the formation of leaf-like ZnO nanoflakes by anodization of zinc foil in a mixture of ammonium sulfate and sodium hydroxide electrolytes under various applied voltage and concentration of sodium hydroxide. The morphology and structure of ZnO nanoflakes were investigated by field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis. In addition, the photocatalytic activity of the prepared nanoflakes zinc oxide was evaluated in the photodegradation of organic dye methylene blue (MB) solution under UV irradiation. It was found that zinc oxide prepared under high concentration of sodium hydroxide and high voltage showed better performance in the photodegradation of methylene blue. Content Type Journal Article Category Photochemistry and Magnetochemistry Pages 2041-2048 DOI 10.1134/S0036024412130171 Authors Muhammad Akhyar Farrukh, Department of Chemistry, GC University Lahore, Lahore, 54000 Pakistan Chin-Kiat Thong, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia Rohana Adnan, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia Mohd Amirrul Kamarulzaman, School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 13

Description:    Bayesian neural networks have been developed, which relate composition, microstructure, and tensile properties of the alloy TIMETAL 6-4 (nominal composition: Ti-6Al-4V (wt pct) after thermomechanical processing (TMP) in the two-phase ( α  +  β )-phase field. The developed networks are able to make interpolative predictions of properties within the ranges of composition and microstructural features that are in the population of the database used for training and testing of the networks. In addition, the neural networks have been used to conduct virtual experiments which permit the functional dependencies of properties on composition and microstructural features to be determined. In this way, it is shown that in the microstructural condition resulting from TMP in the two-phase ( α  +  β ) phase field, the most significant contribution to strength is from solid solution strengthening, with microstructural features apparently influencing the balance of a number of properties. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1498-5 Authors Peter C. Collins, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA Santhosh Koduri, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA Brian Welk, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA Jaimie Tiley, Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright Patterson Air Force Base, Dayton, OH, USA Hamish L. Fraser, Department of Materials Science and Engineering, The Ohio State University, Columbus, OH 43210, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Nanocrystalline iron and oxide dispersion-strengthened (ODS) iron powders (Fe, Fe-Y 2 O 3 , and Fe-Y 2 O 3 -Ti) were prepared by mechanical milling for periods ranging from 1 to 40 hours. The as-milled powders were examined for changes in their particle sizes, crystallite sizes, hardness values, and phases present as a function of milling time. Both the particle and the crystallite sizes of all the three compositions decreased with milling time, while the hardness values of all the three powders increased with milling time because of the crystallite size refinement. At the same crystallite size, the hardness values of Fe-Y 2 O 3 and Fe-Y 2 O 3 -Ti powders were higher than that of the Fe powders. Though, the presence of 40 nm Y 2 O 3 could be established for 2-hour milling, such particles were not resolvable in 40-hour-milled powders. However, SAD patterns confirmed the presence of complex oxide dispersoids in the Fe-Y 2 O 3 and Fe-Y 2 O 3 -Ti powders. The variation of hardness value with the crystallite size and as a function of the milling time can be rationalized on the basis of Hall–Petch crystallite size strengthening in combination with dispersion strengthening (in Fe-Y 2 O 3 - and Fe-Y 2 O 3 -Ti-milled powders) due to dispersoids. The observed double-positive slopes in the Hall–Petch relationship can be explained in terms of an increase in misorientation angle between the crystallites with increasing milling time due to the crystallite rotation driven by disclination dipoles. Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-012-1494-9 Authors R. Vijay, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India M. Nagini, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India J. Joardar, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India M. Ramakrishna, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India A. V. Reddy, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India G. Sundararajan, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Balapur, Hyderabad 500 005, India Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The current trend toward producing lighter vehicles in the automotive industry is driven by the need to conform to the new exhaust emission control regulations. This objective presents a challenge to steel manufacturers. The difficulty lies in designing new alloys with an optimum strength/formability/cost balance for the various components. Here, the key to success lies in controlling the steel microstructure and especially the phase transformations at the smallest possible scale. Among the different alloying elements, light elements such as carbon and boron are of prime importance due to their major effects on the kinetics of phase transformations. Characterization tools combining high spatial and analytical resolution such as secondary ion mass spectrometry (SIMS) and field emission gun-transmission electron microscopy (TEM) were used. In this article, the examples presented are as follows. (1) Boron segregation and precipitation effects to control hardenability in martensitic steels. (2) Local carbon distribution in advanced high-strength steels, with a specific emphasis on martensite tempering. Links have been established between the boron and carbon distribution and the formability. Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-012-1218-1 Authors Josée Drillet, ArcelorMittal Maizières R&D, BP30320, 57283 Maizières-les-Metz Cedex, France Nathalie Valle, SAM Department, CRP-Gabriel Lippmann, 41 rue du Brill, 4422 Belvaux, Luxembourg Thierry Iung, ArcelorMittal Maizières R&D, BP30320, 57283 Maizières-les-Metz Cedex, France Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A methodology for determining the preferred site occupancy of various alloying elements within ordered γ′ precipitates was developed and applied to Rene88 samples. The method utilized atom probe tomography and X-ray diffraction techniques with controlled monochromated synchrotron beams to determine element positions. Samples were solutionized at 1423 K (1150 °C) for 30 minutes and cooled at 24 K/min with subsequent aging at 1033 K (760 °C). The synchrotron X-ray diffraction results indicate that niobium prefers to reside on the aluminum sublattice site of the γ′ phase. Additionally, the results indicate that chromium prefers the nickel sublattice sites, while cobalt is likely to occupy both the aluminum and nickel sublattice sites. The X-ray results on the chromium occupancy disagree with atom probe results from the same alloy that indicate that chromium prefers the aluminum sublattice sites. Content Type Journal Article Category Symposium: Neutron and X-Ray Studies of Advanced Materials V Pages 1-8 DOI 10.1007/s11661-012-1456-2 Authors Jaimie S. Tiley, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA O. Senkov, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA G. Viswanathan, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA S. Nag, Department of Materials Science, Center for Advanced Research and Technology, University of North Texas, Denton, TX 76203, USA J. Hwang, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, Jeonbuk, 565-902 Korea R. Banerjee, Department of Materials Science, Center for Advanced Research and Technology, University of North Texas, Denton, TX 76203, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    By using high-energy synchrotron X-ray and neutron scattering, the local structure of a ternary high-entropy alloy Zr 1/3 Nb 1/3 Hf 1/3 is characterized by means of pair distribution function (PDF) analysis. Results show that this alloy is a body center cubic (b.c.c.) phase in both bulk sample and in a thin film ~1.5  µ m thick. The PDFs obtained from X-ray diffraction and neutron diffraction agree well with each other. The measured PDFs differ from the calculated PDF, particularly in the peak shape of the first two peaks, indicating local lattice distortion due to different atomic sizes in the solid solution. Content Type Journal Article Category Symposium: Bulk Metallic Glasses IX Pages 1-4 DOI 10.1007/s11661-012-1474-0 Authors Wei Guo, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Wojciech Dmowski, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Ji-Yong Noh, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Philip Rack, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Peter K. Liaw, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Takeshi Egami, Joint Institute for Neutron Sciences, Department of Materials Science and Engineering, University of Tennessee, Knoxville, TN 37996, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    In rapidly evolving powder injection molding technology, the wide prevalence of various microstructures demands the powders of smaller particle sizes. The effects of particle size on the sintering behavior are critical to not only shape retention of microstructure but also its mechanical properties. This study investigates the effects of three different particle sizes on the sintering behavior of the 316L stainless steel (STS316L) samples, prepared by powder injection molding, via the dilatometry experiments. For this purpose, the STS316L powders of three different mean particle sizes, i.e. , 2.97, 4.16, and 8.04  μ m, were produced for STS316L. The samples for the dilatometry test were prepared through powder-binder mixing, injection molding, and solvent and thermal debinding. Dilatometry experiments were carried out with the samples in a H 2 atmosphere at three different heating rates of 3, 6, and 10 K/min. The shrinkage data obtained by dilatometry experiments was collected and analyzed to help understand the densification and the sintering behaviors in terms of particles size and heating rate. The master sintering curve (MSC) model was used to quantify the effects of particle sizes. In addition, we investigated the microstructure evolutions in terms of particles sizes. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1477-x Authors Dong Yong Park, Department of Mechanical Engineering, and Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk 790-784, Korea Shi W. Lee, Department of Industrial Engineering, Pusan National University, Busan, 609-735 Korea Seong Jin Park, Department of Mechanical Engineering, and Division of Advanced Nuclear Engineering, POSTECH, Pohang, Gyungbuk 790-784, Korea Young-Sam Kwon, CetaTech, Inc., Sacheon, Gyungnam 664-950, Korea Isamu Otsuka, MP Development & Engineering Department, Epson Atmix Corporation, Hachinohe, Aomori 039-1161, Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The microstructure and properties of a precipitation-hardenable Ni-48Ti-25Pd (at. pct) shape memory alloy have been investigated as a function of various aging conditions. Both the hardness and martensitic transformation temperatures increased with increasing aging time up to 100 hours at 673 K (400 °C), while no discernable differences were observed after heat treatment at 823 K (550 °C), except for a slight decrease in hardness. For aging at 673 K (400 °C), these effects were attributed to the formation of nano-scale precipitates, while precipitation was absent in the 823 K (550 °C) heat-treated specimens. The precipitation-strengthened alloy exhibited stable pseudoelastic behavior and load-biased-shape memory response with little or no residual strains. The precipitates had a monoclinic base-centered structure, which is the same structure as the P-phase recently reported in Ni(Pt)-rich NiTiPt alloys. 3D atom probe analysis revealed that the precipitates were slightly enriched in Ni and deficient in Pd and Ti as compared with the bulk alloy. The increase in martensitic transformation temperatures and the superior dimensional stability during shape memory and pseudoelastic testing are attributed to the fine precipitate phase and its effect on matrix chemistry, local stress state because of the coherent interface, and the ability to effectively strengthen the alloy against slip. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1481-1 Authors Taisuke T. Sasaki, Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, USA B. Chad Hornbuckle, Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, USA Ronald D. Noebe, Structures and Materials Division, NASA Glenn Research Center, Cleveland, OH, USA Glen S. Bigelow, Structures and Materials Division, NASA Glenn Research Center, Cleveland, OH, USA Mark L. Weaver, Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, USA Gregory B. Thompson, Department of Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    This article compares chromium evaporation characteristics of chromia- and alumina-forming alloys at high temperatures [1123 K and 1223 K (800 °C to 950 °C)] in humid air (3 and 12 pct H 2 O) and presents a mechanistic understanding of variation in chromium evaporation on the basis of their oxide scale morphologies. For this study, an alloy from each of the distinct chromia-forming, alumina-forming, and chromia-alumina transition characteristics was selected ( i.e. , an alumina-forming alloy (Aluchrom YHf), a chromia-forming alloy (AISI 310S-austentic stainless steel), and an alloy that undergoes transition from chromia to alumina formation (Nicrofer6025 HT)). For generating baseline chromium evaporation data, pure chromium oxide was also tested. The chromium evaporation rate decreased in the order pure chromium oxide 〉 AISI 310S 〉 Nicrofer6025 HT 〉 Aluchrom YHf. Surface morphologies, cross sections, and chemical characteristics of oxide scales were examined by scanning electron microscopy and energy dispersive X-ray spectroscopy and focused ion beam. The variation in chromium evaporation of different alloys is explained on the basis of physical and chemical characteristics of the oxide scales. Content Type Journal Article Pages 1-14 DOI 10.1007/s11661-012-1492-y Authors Le Ge, Department of Chemical, Materials & Biomolecular Engineering, Center for Clean Energy Engineering, University of Connecticut, Storrs, CT 06269, USA Atul Verma, Department of Chemical, Materials & Biomolecular Engineering, Center for Clean Energy Engineering, University of Connecticut, Storrs, CT 06269, USA Richard Goettler, Rolls-Royce Fuel Cell Systems (US) Inc., North Canton, OH 44720, USA David Lovett, Rolls-Royce Fuel Cell Systems (US) Inc., North Canton, OH 44720, USA R. K. Singh Raman, Departments of Mechanical & Aerospace Engineering, and Chemical Engineering, Monash University, Melbourne, VIC 3800, Australia Prabhakar Singh, Department of Chemical, Materials & Biomolecular Engineering, Center for Clean Energy Engineering, University of Connecticut, Storrs, CT 06269, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    In this study, the accumulative roll bonding and folding (ARBF) process was used for manufacturing nanostructured aluminum/copper multilayered composites. Textural evolution during the ARBF process of composites was evaluated using X-ray diffraction. Microstructural observation of some samples was evaluated by scanning electron microscopy and transmission electron microscopy. The ARBF process induced formation of a strong preferred orientation along the β-fiber and also to the pronounced copper texture component. In the aluminum side, occurrence of dynamic recovery reduced the intensity of the β-fiber rolling texture due to change in dislocation structure and decrease in the degree of strain hardening. On the other hand, occurrence of discontinuous dynamic recrystallization at the third and fourth ARBF cycles led to decreasing the intensity of fibers and texture components in the copper side. The average grain sizes of the final sample for the copper and aluminum sides were ~50 and ~200 nm, respectively. Content Type Journal Article Pages 1-12 DOI 10.1007/s11661-012-1503-z Authors Mohammad Reza Toroghinejad, Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan, Iran Roohollah Jamaati, Department of Materials Engineering, Isfahan University of Technology, 84156-83111 Isfahan, Iran Majid Hoseini, Department of Mining, Metals and Materials Engineering, McGill University, Montreal, QC H3A 2B2, Canada Jerzy A. Szpunar, Department of Mechanical Engineering, University of Saskatchewan, Saskatoon, SK S7N 5A9, Canada Jan Dutkiewicz, Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, ul. Reymonta 25, 30-059 Krakow, Poland Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Al- Cu alloys (such as A206) offer high strength and high fracture toughness at both room and elevated temperatures. However, their widespread applications are limited because of their high susceptibility to hot tearing. This article presents a nanotechnology approach to enhance hot-tearing resistance for A206. Specifically, γ-Al 2 O 3  nanoparticles were used, and their effects on the hot-tearing resistance of the as-cast Al-4.5Cu alloy (A206) were investigated. While it is well known that grain refinement can improve the hot-tearing resistance of cast Al alloys, the current study demonstrated that nanoparticles can be much more effective in the case of A206. The hot-tearing susceptibilities (HTSs) of A206 alloy and its Al 2 O 3  nanocomposite were evaluated by constrained rod casting (CRC) with a steel mold. Monolithic A206 and M206 (the Ti-free version of A206) alloys with the B contents of 20, 40, and 300 ppm from an Al-5Ti-1B master alloy addition were also cast under the same conditions for comparison. The results showed that with an addition of 1 wt pct γ-Al 2 O 3  nanoparticles, the extent of hot tearing in A206 alloys was markedly reduced to nearly that of A356, an Al-Si alloy highly resistant to hot tearing. As compared with grain-refined A206 or M206, the hot-tearing resistance of the nanocomposites was significantly better, even though the grain size was not reduced as much. Microstructural analysis suggested that γ-Al 2 O 3  nanoparticles modified the solidification microstructure of the eutectic of θ-Al 2 Cu and α-Al, as well as refined primary grains, resulting in the enhancement of the hot-tearing resistance of A206 to a level similar to that of A356 alloy. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1531-8 Authors Hongseok Choi, Department of Mechanical Engineering, University of Wisconsin-Madison, 1035 Mechanical Engineering Bldg., 1513 University Avenue, Madison, WI 53706, USA Woo-hyun Cho, Department of Mechanical Engineering, University of Wisconsin-Madison, 1035 Mechanical Engineering Bldg., 1513 University Avenue, Madison, WI 53706, USA Hiromi Konishi, Departments of Geoscience and Mechanical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA Sindo Kou, Department of Materials Science and Engineering, University of Wisconsin-Madison, 1509 University Avenue, Madison, WI 53706, USA Xiaochun Li, Department of Mechanical Engineering, University of Wisconsin-Madison, 1035 Mechanical Engineering Bldg., 1513 University Avenue, Madison, WI 53706, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The kinetics of the γ′ phase dissolution have been studied at 1473 K and 1523 K (1200 °C and 1250 °C) for CMSX-4 ® alloy. Interrupted creep tests at 1323 K (1050 °C) and pure thermal aging at 1373 K (1100 °C) have been used to vary the initial γ′ morphology. Subsequent dissolution studies were conducted with or without an applied load. Differences in γ′ dissolution kinetics were observed between the dendrite cores and the interdendritic regions, resulting from the chemical microsegregations remaining after the standard heat treatments. It is shown that the initial γ′ morphology, the relaxation of the coherency stresses and the accumulated plastic strain are critical parameters controlling the dissolution kinetics. An increase of the accumulated plastic strain leads to an increase of the dissolution kinetics, whatever the location in the dendritic structure. In addition, once a given accumulated creep strain is reached prior to the dissolution tests ( i.e. , a given dislocations density), the dissolution kinetics are the same at 1473 K and 1523 K (1200 °C and 1250 °C). A modified equation of the recently developed Polystar model is proposed to incorporate the role of the accumulated plastic strain on the γ′ dissolution kinetics and to achieve a better predictability of the creep deformation under non-isothermal loading paths. Content Type Journal Article Pages 1-16 DOI 10.1007/s11661-012-1397-9 Authors Rémi Giraud, Turbomeca - SAFRAN Group, Département Matériaux, Procédés et Expertises, 64511 Bordes Cedex, France Zéline Hervier, Turbomeca - SAFRAN Group, Département Matériaux, Procédés et Expertises, 64511 Bordes Cedex, France Jonathan Cormier, Institut Pprime, CNRS—ENSMA—Université de Poitiers, UPR CNRS 3346, Département de Physique et Mécanique des Matériaux, ENSMA—Téléport 2, 1 avenue Clément Ader, BP 40109, 86961 Futuroscope - Chasseneuil Cedex, France Gilles Saint-Martin, Turbomeca - SAFRAN Group, Département Matériaux, Procédés et Expertises, 64511 Bordes Cedex, France Florence Hamon, Institut Pprime, CNRS—ENSMA—Université de Poitiers, UPR CNRS 3346, Département de Physique et Mécanique des Matériaux, ENSMA—Téléport 2, 1 avenue Clément Ader, BP 40109, 86961 Futuroscope - Chasseneuil Cedex, France Xavier Milhet, Institut Pprime, CNRS—ENSMA—Université de Poitiers, UPR CNRS 3346, Département de Physique et Mécanique des Matériaux, ENSMA—Téléport 2, 1 avenue Clément Ader, BP 40109, 86961 Futuroscope - Chasseneuil Cedex, France José Mendez, Institut Pprime, CNRS—ENSMA—Université de Poitiers, UPR CNRS 3346, Département de Physique et Mécanique des Matériaux, ENSMA—Téléport 2, 1 avenue Clément Ader, BP 40109, 86961 Futuroscope - Chasseneuil Cedex, France Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The effects of processing temperature on the deep-rolling response of three medium carbon bar steels, a quenched and tempered 4140 alloy, a 0.34C, 1.21Mn, 0.66Si nontraditional bainitic alloy, and a 0.36C, 1.37Mn V-microalloyed ferrite plus pearlite steel, was assessed through bending fatigue. The significantly different deformation behaviors of the three alloys were characterized through standard and nonstandard quasi-static and cyclic uniaxial tension and compression tests at room temperature (RT) and in situ at temperatures up to 634 K. Deep rolling, performed at RT and at elevated temperature (HT) in the dynamic strain-aging (DSA) regime, increased measured endurance limits by 51-62 pct (RT) and 96-117 pct (HT) as compared with the baseline condition. The enhanced fatigue performance by RT deep rolling primarily reflected the effects of the introduction of favorable residual stresses. The improved fatigue performance from HT deep rolling was attributed to the enhanced resistance to strain reversal of the material deformed during deep rolling, due to a change in deformation mechanism from dislocation-interstitial interactions in the DSA regime during processing, which inhibited mechanically induced relaxation of residual stress during cyclic loading. Content Type Journal Article Pages 1-16 DOI 10.1007/s11661-012-1371-6 Authors M. D. Richards, Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, CO 80401, USA M. E. Burnett, The Timken Co., Canton, OH 44706, USA J. G. Speer, Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, CO 80401, USA D. K. Matlock, Advanced Steel Processing and Products Research Center, Colorado School of Mines, Golden, CO 80401, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The refinement in size and modification in morphology for primary Mg 2 Si depended significantly on Sb contents in Mg-4Si alloys. Adding Sb into melts evidently increased the nucleus numbers of primary Mg 2 Si crystals. Moreover, the preferential growth along á 100 ñ directions in dendritic crystals was restricted greatly due to the Si sites being substituted by Sb in Mg 2 Si lattices, resulting in modified primary Mg 2 Si crystals growing to octahedral morphology surrounded by {111} planes; therefore, the modification process could be called adsorption and poisoning mechanisms. Content Type Journal Article Pages 1-7 DOI 10.1007/s11661-012-1317-z Authors Hui-Yuan Wang, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Qian Li, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Bo Liu, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Nan Zhang, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Lei Chen, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Jin-Guo Wang, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Qi-Chuan Jiang, Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering, Jilin University, Nanling Campus, Changchun, 130025 People’s Republic of China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description: Tungsten-copper composites with various copper nano-particles volume fractions were manufactured and examined. Tungsten-copper composites with 20 pct, 25 pct, and 30 pct volume fractions were mechanically mixed and sintered. spark plasma sintering (SPS) method was used for samples preparation at two different sintered temperatures 1273 K and 1373 K (1000 °C and 1100 °C). The effect of copper nano-particles on the bulk density, hardness, the coefficient of thermal expansion (CTE), electrical conductivity, and stress-strain behavior of the produced composites were studied. The hardness was found to decrease with the increase of the copper volume fraction in the composites. Conversely, the CTE and electrical conductivity increases with the increase of the copper volume fraction in the composites. Furthermore, the elastic modulus were extracted from tensile stress-strain behavior were found to increase with the increase of the copper volume fraction in the composites. Finally, the fracture surface roughness was studied using high resolution optical investigations and was noticeably higher with the increase of the copper volume fraction in the composites. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1396-x Authors Medhat Awad El-Hadek, Department of Mechanical Design & Production, Faculty of Engineering at Port-Said, Port-Said University, Port-Fouad, Port-Said, 42523 Egypt Saleh Hamada Kaytbay, Department of Mechanical Engineering, Faculty of Engineering at Benha, Benha University, Benha, Egypt Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A series of Al-5 wt pct Si alloys with Yb additions (up to 6100 ppm) have been investigated using thermal analysis and multiscale microstructure characterization techniques. The addition of Yb was found to cause no modification effect to a fibrous morphology involving Si twinning; however, a refined plate-like eutectic structure was observed. The Al 2 Si 2 Yb phase was observed with Yb addition level of more than 1000 ppm. Within the eutectic Al and Si phases, the Al 2 Si 2 Yb phase was also found as a precipitation from the remained liquid. No Yb was detected in the α-Al matrix or plate-like Si particle, even with Yb addition up to 6100 ppm. The absence of Yb inside the eutectic Si particle may partly explain why no significant Si twinning was observed along {111} Si planes in the eutectic Si particle. In addition, the formation of the thermodynamic stable YbP phases is also proposed to deteriorate the potency of AlP phase in Al alloys. This investigation highlights to distinguish the modification associated with the ever present P in Al alloys. We define modification as a transition from faceted to fibrous morphology, while a reduction of the Si size is termed refinement. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1410-3 Authors J. H. Li, Department of Metallurgy, University of Leoben, 8700 Leoben, Austria S. Suetsugu, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya, 468-8511 Japan Y. Tsunekawa, Toyota Technological Institute, Hisakata 2-12-1, Tempaku, Nagoya, 468-8511 Japan P. Schumacher, Department of Metallurgy, University of Leoben, 8700 Leoben, Austria Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Kitagawa-Takahashi diagram combines the endurance limit of a smooth specimen and the crack propagation threshold in a fracture mechanics specimen into single diagram thus providing the connection between the stress or strain-life and damage tolerance approaches. The diagram is modified by considering that (a) fatigue requires two independent load-parameters for unambiguous description, (b) long crack growth behavior defines the material resistance under constant stress amplitudes along with the associated R -ratio effects, (c) remote applied stresses and localized plasticity-effects can be combined to provide the total mechanical force opposing the material resistance leading to crack initiation, growth and failure describable in the diagram, (d) localized plasticity contributes to internal stresses that either augment or retard the remote stresses, and finally (e) the magnitude and gradient of these internal stresses determine the condition for propagation and/or non-propagation of the incipient cracks that form either at pre-existing stress concentrations or in situ formed stress concentrations due to localized plasticity. Localized plasticity forms the basis for the additional crack tip driving forces in either accelerating or decelerating crack growth kinetics thereby providing conditions for either crack arrest with resulting non-propagating cracks or for continuous uninterrupted crack growth. Internal stresses are generated during fatigue damage in the form of dislocation pile-ups, intrusions and extrusions. The analysis shows that critical magnitude and gradient of the internal stresses are required for an incipient crack to grow continuously, failing which crack arrest can occur. The methodology is based on separating the mechanically introduced crack tip driving forces vs the material resistance; the later can be extracted from long-crack growth data under constant amplitudes. Analysis of incipient short cracks growing under the elastic-plastic notch tip stress fields are analyzed systematically for various elastic stress concentrations, K t , and notch-tip radii, ρ. A general formulation is developed based on the calculations that can be incorporated into the unified life predication model that is being developed. Content Type Journal Article Category Symposium: Environmental Damage in Structural Materials Under Static/Dynamic Loads at Ambient Temperature Pages 1-15 DOI 10.1007/s11661-012-1416-x Authors K. Sadananda, Technical Data Analysis, 3190 Fairview Park Drive, Suite 650, Falls Church, VA 22042, USA S. Sarkar, Technical Data Analysis, 3190 Fairview Park Drive, Suite 650, Falls Church, VA 22042, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Interference (cross-correlation) effects are present in the X-ray powder diffraction pattern of a polycrystalline aggregate. In an experimental diffraction pattern, the information is highly overlapped and can be confused with other effects. In this article, it is shown that the analysis of the patterns calculated from a cluster equilibrated via molecular dynamics simulation allows those effects to be separated. Extra intensity is observed, because of the presence of the grain boundaries contribution which is unexpectedly not that of an amorphous phase. Content Type Journal Article Category Symposium: Neutron and X-Ray Studies of Advanced Materials V Pages 1-6 DOI 10.1007/s11661-012-1428-6 Authors A. Leonardi, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano, 77, 38123 Trento, Italy M. Leoni, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano, 77, 38123 Trento, Italy P. Scardi, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano, 77, 38123 Trento, Italy Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Particle-stimulated nucleation (PSN) is investigated in Nb-containing ferritic stainless steel. Coarse-grained sheets were cold rolled to 80 pct thickness reduction and annealed from 973 K to 998 K (700 °C to 725 °C) to obtain partially recrystallized microstructures. Electron backscatter diffraction was performed around coarse niobium carbonitride particles (larger than 1  μ m) within coarse grains (~1 mm), with different host orientations in both deformed and annealed states. In the deformed state, the deformation zones around both spherical and rectangular particles were investigated. The local lattice rotations about the transverse direction necessary to accommodate the particle-matrix strain incompatibility were observed in all grains investigated. After annealing, recrystallization occurs preferentially around coarse particles at the initial stages of recrystallization. Based on a total number of 130 grains nucleated via PSN, we observe both, randomly oriented and minor {111}〈110〉 oriented texture components. The results also reveal that PSN in this material is not associated with a specific host orientation. Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-012-1408-x Authors Rodrigo Pinto de Siqueira, Departamento de Engenharia de Materiais, Escola de Engenharia de Lorena, University of Sao Paulo, Lorena, SP 12600-970, Brazil Hugo Ricardo Zschommler Sandim, Departamento de Engenharia de Materiais, Escola de Engenharia de Lorena, University of Sao Paulo, Lorena, SP 12600-970, Brazil Dierk Raabe, Max-Planck Institut für Eisenforschung (MPIE), 40237 Düsseldorf, Germany Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    This work analyzes the effect of different additions of silicon (0 to 5.0 pct) on the structure of a high-Chromium white cast iron, with chromium content of 16.8 pct and carbon 2.56 pct. The alloys were analyzed in both as-cast and heat-treated conditions. Casting was undertaken in metallic molds that yielded solidification rates faster than in commercial processes. Nevertheless, there was some degree of segregation of silicon; this segregation resulted in a refinement in the microstructure of the alloy. Silicon also generated a greater influence on the structure by destabilizing the austenitic matrix, and promoted greater precipitation of eutectic carbides. Above 3 pct silicon, pearlite formation occurred in preference to martensite. After the destabilization heat treatment, the matrix structure of the irons up to 3 pct Si consisted of secondary carbides in a martensitic matrix with some retained austenite; higher Si additions produced a ferritic matrix. The different as-cast and heat-treated microstructures were correlated with selected mechanical properties such as hardness, matrix microhardness, and fracture toughness. Silicon additions increased matrix microhardness in the as-cast conditions, but the opposite phenomenon occurred in the heat-treated conditions. Microhardness decreased as silicon content was increased. Bulk hardness showed the same behavior. Fracture toughness was observed to increase up to 2 pct Si, and then decreased for higher silicon contents. These results are discussed in terms of the effect of eutectic carbides’ size and the resulting matrix due to the silicon additions. Content Type Journal Article Pages 1-17 DOI 10.1007/s11661-012-1434-8 Authors A. Bedolla-Jacuinde, Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Mexico, Mexico M. W. Rainforth, Department of Engineering Materials, The University of Sheffield, Sheffield, U.K. I. Mejía, Instituto de Investigaciones Metalúrgicas, Universidad Michoacana de San Nicolás de Hidalgo, Mexico, Mexico Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description: HSLA-100 steel with high content of alloying elements (nominally in wt pct, 3.5 Ni, 1.6 Cu, and 0.6Mo) is now used to produce heavy plates for constructing a hull and drilling platform. We proposed here a substantially leaner steel composition (containing 1.7 Ni, 1.1 Cu, and 0.5Mo) to produce a heavy plate to 80 mm thickness with mechanical properties comparable with those of the HSLA-100 grade. A continuous cooling transformation (CCT) diagram of the steel was constructed. Key parameters of thermal treatment and revealing mechanisms of strengthening and toughening were derived based on industrial production trials. The microstructures of the 80-mm-thick plate were lath-like bainite (LB) at near surface of the quarter thickness ( t /4), and granular bainite (GB)+LB at center thickness ( t /2) after solutionizing and water quenching (Q). The effect of tempering (T) on the microstructures and properties of the plate was investigated. Excellent combination of room temperature strength and low-temperature Charpy V-notch (CVN) toughness approximately equivalent to that of the HSLA 100 grade (YS 〉 690 MPa, CVN energy 〉100 J even at 193 K [−80 °C]) was achieved in the plate treated by the QT process with tempering temperature of 898 K (625 °C). The combination of strength and toughness at t /4 is superior to that at t /2 of the plate under both as-quenched and QT conditions. This result is attributed to that the fraction of high-angle grain boundaries (HAGBs) at t /4 is higher than that at t /2. Content Type Journal Article Pages 1-16 DOI 10.1007/s11661-012-1389-9 Authors Dongsheng Liu, Institute of Research of Iron and Steel, Shasteel, Jinfeng, Zhangjiagang, 215625 Jiangsu, People’s Republic of China Binggui Cheng, Institute of Research of Iron and Steel, Shasteel, Jinfeng, Zhangjiagang, 215625 Jiangsu, People’s Republic of China Yuanyuan Chen, Institute of Research of Iron and Steel, Shasteel, Jinfeng, Zhangjiagang, 215625 Jiangsu, People’s Republic of China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description: The atomic and electronic structures of several Ca-Mg-TM amorphous alloys (TM is Cu or Zn) have been analyzed using ab initio molecular dynamics simulation and neutron diffraction. Partial pair distribution functions have been produced and the pair bond distances and partial coordination numbers have been reported for these alloys. Similarities and differences in the amorphous structures of the Ca-Mg-Cu and Ca-Mg-Zn alloys have been discussed. Strong interactions between Ca-Cu, Mg-Cu and Ca-Zn atom pairs rooted from the orbital hybridization of the s - p - d electrons have been recognized to result in noticeable shortening of respective atom pair bond distances and pronounced chemical short range ordering near the TM atoms. Voronoi tessellation analysis has shown that the polytetrahedral-type clusters and five-coordinated atom pairs dominate in the amorphous structures, which indicates that tetrahedra and pentagonal bi-pyramids are the main building blocks in these amorphous alloys. Content Type Journal Article Category Symposium: Bulk Metallic Glasses IX Pages 1-10 DOI 10.1007/s11661-012-1406-z Authors O. N. Senkov, UES, Inc., Dayton, OH, USA Y. Q. Cheng, Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The current investigation reports detailed study on the microstructural evolution in the suction cast hypereutectic Ti 71 Fe 29− x Sn x alloys during Sn addition with x  = 0, 2, 2.5, 3, 3.85, 4.5, 6, and 10 at. pct and the solidification of these ternary alloys using SEM and TEM. These alloys have been prepared by melting high-purity elements using vacuum arc melting furnace under high-purity argon atmosphere. This was followed by suction casting these alloys in the water-cooled split Cu molds of diameters, ϕ = 1 and 3 mm, under argon atmosphere. The results indicate the formation of binary eutectic between bcc solid solution β-Ti and B2 FeTi in all alloys. β-Ti undergoes eutectoid transformation, β-Ti → α-Ti + FeTi, during subsequent solid-state cooling, leading to formation of hcp α-Ti and FeTi. For alloys x  〈 2, the primary FeTi forms from the liquid before the formation of eutectic with minute scale Ti 3 Sn phase. For alloys with 2 ≥  x  ≤ 10, the liquid is found to undergo ternary quasi-peritectic reaction with primary Ti 3 Sn, L+Ti 3 Sn → β-Ti+FeTi, leading to formation of another kind of FeTi. In all the other alloy compositions (3.85 ≥  x  ≤ 10), Ti 3 Sn and FeTi dendrites are observed in the suction cast alloys with profuse amount of Ti 3 Sn being formed for alloys with x  ≥ 4.5. The current study conclusively proves that the liquid undergoes ternary quasi-peritectic reaction involving four phases, L + Ti 3 Sn → β-Ti + FeTi, which lies at the invariant point Ti 69.2±0.8 Fe 27.4±0.7 Sn 3.4±0.2 (denoted by P). Below P, there is one univariant reaction, i.e. , L → β-Ti + FeTi for all alloy compositions, whereas above P, liquid undergoes one of the univariant reactions, i.e. , L + β-Ti → Ti 3 Sn (Sn = 2, 2.5, 3, and 4.5 at. pct) or L + FeTi → Ti 3 Sn for alloys (Sn = 6, 10 at. pct). For alloy with Sn = 3.85 at. pct, the ternary quasi-peritectic reaction is co-operated by two monovariant eutectic reactions, i.e. , L → β-Ti + FeTi below P and L → FeTi + Ti 3 Sn above P. Detailed microstructural information allows us to construct liquidus projection of the investigated alloys. The results are critically discussed in the light of available literature data. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1404-1 Authors Sumanta Samal, Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016 Uttar Pradesh, India Barnali Mondal, Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016 Uttar Pradesh, India Krishanu Biswas, Department of Materials Science and Engineering, Indian Institute of Technology Kanpur, Kanpur, 208016 Uttar Pradesh, India Govind, Materials Science Division, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Trivandrum, 695022 Kerala, India Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Material strengthening and embrittlement are controlled by complex intrinsic interactions between dislocations and hydrogen-induced defect structures that strongly alter the observed deformation mechanisms in materials. In this study, we reported molecular statics simulations at zero temperature for pure α-Fe with a single H atom at an interstitial and vacancy site, and two H atoms at an interstitial and vacancy site for each of the 〈100〉, 〈110〉, and 〈111〉 symmetric tilt grain boundary (STGB) systems. Simulation results show that the grain boundary (GB) system has a smaller effect than the type of H defect configuration (interstitial H, H-vacancy, interstitial 2H, and 2H-vacancy). For example, the segregation energy of hydrogen configurations as a function of distance is comparable between symmetric tilt GB systems. However, the segregation energy of the 〈100〉 STGB system with H at an interstitial site is 23 pct of the segregation energy of 2H at a similar interstitial site. This implies that there is a large binding energy associated with two interstitial H atoms in the GB. Thus, the energy gained by this H-H reaction is ~54 pct of the segregation energy of 2H in an interstitial site, creating a large driving force for H atoms to bind to each other within the GB. Moreover, the cohesive energy values of 125 STGBs were calculated for various local H concentrations. We found that as the GB energy approaches zero, the energy gained by trapping more hydrogen atoms is negligible and the GB can fail via cleavage. These results also show that there is a strong correlation between the GB character and the trapping limit (saturation limit) for hydrogen. Finally, we developed an atomistic modeling framework to address the probabilistic nature of H segregation and the consequent embrittlement of the GB. These insights are useful for improving ductility by reengineering the GB character of polycrystalline materials to alter the segregation and embrittlement behavior in α-Fe. Content Type Journal Article Category Symposium: Environmental Damage in Structural Materials under Static/Dynamic Loads at Ambient Temperature Pages 1-11 DOI 10.1007/s11661-012-1430-z Authors Kiran N. Solanki, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287, USA Mark A. Tschopp, Center for Advanced Vehicular Systems, 200 Research Blvd., Starkville, MS 39759, USA Mehul A. Bhatia, School for Engineering of Matter, Transport, and Energy, Arizona State University, Tempe, AZ 85287, USA Nathan R. Rhodes, Center for Advanced Vehicular Systems, 200 Research Blvd., Starkville, MS 39759, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Shear localizations with different strains in annealed copper were obtained by a modified split Hopkinson pressure bar. Microstructure and microtexture evolution of the shear localization regions were examined using optical microscopy, electron backscatter diffraction technique, and transmission electron microscopy. The results show that both the mechanical response and deformation behavior are correlated closely to the shear strains. The elongated dislocation cells, stretched subgrains, and the refinement of subgrains are observed within shear localizations during dynamic deformation. Ultrafine grains of 100 to 300 nm with high-angle-boundaries are produced within the shear band with the shear strain of 5.8. Microtexture characterization reveals that a stable orientation, in which 〈110〉 directions of the crystals tend to align with the shear direction, develops both in the deformation and recrystallization areas. The {111} planes of the crystals tend to parallel to the shear plane in the deformation area, whereas the aggregated extent of this orientation becomes weak in the recrystallization area. In addition, some grains exist with the {100} planes parallel to the shear plane in the deformation and recrystallization areas. The rotational dynamic recrystallization is a reasonable mechanism for the microstructure evolution. The effects of cooling stage on the growth of grains and the change of dislocation density are estimated as a complementarity to this mechanism. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1421-0 Authors Lin Tang, School of Materials Science and Engineering, Central South University, Changsha, 410083 P.R. China Zhiyong Chen, School of Materials Science and Engineering, Central South University, Changsha, 410083 P.R. China Congkun Zhan, School of Materials Science and Engineering, Central South University, Changsha, 410083 P.R. China Xuyue Yang, School of Materials Science and Engineering, Central South University, Changsha, 410083 P.R. China Chuming Liu, School of Materials Science and Engineering, Central South University, Changsha, 410083 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Silver-tin oxide electrical contact material with 10 wt pct stannic oxide and balance nanosized and micronsized silver was developed successfully. Stannic oxide particles chemically coated by a layer of silver nanospheres are homogeneously dispersed in a silver microcrystalline matrix made by chemical synthesis. The material processed by pressing-sintering-repressing exhibited enhanced properties: density: 97.1 to 97.9 pct relative density, Vickers hardness: 103 to 115, electrical conductivity: 65 to 69 pct IACS, volumetric shrinkage: 28.9 to 30.9 pct, and a very fine and uniform microstructure. Content Type Journal Article Category Communication Pages 1-6 DOI 10.1007/s11661-012-1424-x Authors Magdalena Lungu, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Stefania Gavriliu, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Elena Enescu, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Mariana Lucaci, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Violeta Tsakiris, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Gimi Rimbu, National Institute for Research and Development in Electrical Engineering ICPE-CA, 030138 Bucharest 3, Romania Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Al 413/Mg couples were prepared by the compound casting process. Characterization of the interface by an optical microscope and scanning electron microscope (SEM) showed that a relatively uniform interface composed of three different layers is formed at the interface. The thickness of the interface depended on the melt/insert volume ratio (VR) significantly and was 80 and 470  μm  in 1.25 and 3 VRs, respectively. The results of the energy dispersive X-ray spectroscopy (EDS), wavelength dispersive X-ray spectroscopy (WDS), and X-ray diffraction analysis showed that the interface layers are mainly composed of Al 3 Mg 2 , Al 12 Mg 17 , and Mg 2 Si intermetallic compounds. An accumulation of magnesium oxide films was detected within the (Al 12 Mg 17  +  δ ) eutectic structure of the interface next to the magnesium base metal. Despite different thicknesses of the interface, shear strengths of the Al 413/Mg couples prepared in 1.25 and 3 VRs were almost same. The study of the fracture surfaces of the Al 413/Mg couples revealed that the accumulated magnesium oxide films act as a weak point for initiation of longitudinal cracks and failure of the joint. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1296-0 Authors E. Hajjari, Department of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Tehran, Iran M. Divandari, Department of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Tehran, Iran S. H. Razavi, Department of Metallurgy and Materials Engineering, Iran University of Science and Technology, 16846-13114 Tehran, Iran T. Homma, Research Center for Advanced Magnesium Technology, Nagaoka University of Technology, Nagaoka, 940-2188 Japan S. Kamado, Research Center for Advanced Magnesium Technology, Nagaoka University of Technology, Nagaoka, 940-2188 Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A stable Ni-rich Ni-29.7Ti-20Hf (at. pct) shape memory alloy, with relatively high transformation temperatures, was shown to exhibit promising properties at lower raw material cost when compared to typical NiTi-X (X = Pt, Pd, Au) high-temperature shape memory alloys (HTSMAs). The excellent dimensional stability and high work output for this alloy were attributed to a coherent, nanometer size precipitate phase observed using transmission electron microscopy. To establish an understanding of the role of these precipitates on the microstructure and ensuing stability of the NiTiHf alloy, a detailed study of the micromechanical and microstructural behaviors was performed. In-situ neutron diffraction at stress and temperature was used to obtain quantitative information on phase-specific internal strain, texture, and phase volume fractions during both isothermal and isobaric testing of the alloy. During isothermal testing, the alloy exhibited low isothermal strains due to limited detwinning, consistent with direct measurements of the bulk texture through neutron diffraction. This limited detwinning was attributed to the pinning of twin and variant boundaries by the dispersion of fine precipitates. During isobaric thermal cycling at 400 MPa, the high work output and near-perfect dimensional stability was attributed to the presence of the precipitates that act as homogeneous sources for the nucleation of martensite throughout the material, while providing resistance to irrecoverable processes such as plastic deformation. Content Type Journal Article Pages 1-14 DOI 10.1007/s11661-012-1297-z Authors O. Benafan, Advanced Materials Processing and Analysis Center (AMPAC), Mechanical, Materials, and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA R. D. Noebe, Structures and Materials Division, NASA Glenn Research Center, Cleveland, OH 44135, USA S. A. Padula II, Structures and Materials Division, NASA Glenn Research Center, Cleveland, OH 44135, USA R. Vaidyanathan, Advanced Materials Processing and Analysis Center (AMPAC), Mechanical, Materials, and Aerospace Engineering, University of Central Florida, Orlando, FL 32816, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Steel is a particularly challenging material to semisolid process because of the high temperatures involved and the potential for surface oxidation. Hot-rolled X210CrW12 tool steel was applied as a feedstock for thixoforming. The samples were heated up to 1525 K (1250 °C) to obtain 30 pct of the liquid phase. They were pressed in the semisolid state into a die preheated up to 473 K (200 °C) using a device based on a high-pressure die casting machine. As a result, a series of main bucket tooth thixo-casts for a mining combine was obtained. The microstructure of the thixo-cast consisted of austenite globular grains (average grain size 46 μ m) surrounded by a eutectic mixture (ferrite, austenite, and M 7 C 3 carbides). The average hardness of primary austenite grains was 470 HV 0.02 and that of eutectic 551 HV 0.02 . The X-ray analysis confirmed the presence of 11.8 pct α -Fe, 82.4 pct γ -Fe, and 5.8 pct M 7 C 3 carbides in the thixo-cast samples. Thermal and dilatometric effects were registered in the solid state, and the analysis of curves enabled the determination of characteristic temperatures of heat treatment: 503 K, 598 K, 693 K, 798 K, 828 K, 903 K, and 953 K (230 °C, 325 °C, 420 °C, 525 °C, 555 °C, 630 °C, 680 °C). The thixo-casts were annealed at these temperatures for 2 hours. During annealing in the temperature range 503 K to 693 K (230 °C to 420 °C), the hardness of primary globular grains continuously decreased down to 385HV 0.02 . The X-ray diffraction showed a slight shift of peaks responsible for the tension release. Moreover, after the treatment at 693 K (420 °C), an additional peak from precipitated carbides was observed in the X-ray diffraction. Thin plates of perlite (average hardness 820 HV 0.02 ) with carbide precipitates appeared at the boundaries of globular grains at 798 K (525 °C). They occupied 17 pct of the grain area. Plates of martensite were found in the center of grains, while the retained austenite was observed among them (average hardness of center grains was 512 HV 0.02 ). A nearly complete decomposition of metastable austenite was achieved after tempering at 828 K (555 °C) due to prevailing lamellar pearlite structure starting at grain boundaries and the martensite located in the center of the grains. The X-ray analysis confirmed the presence of 3.4 pct γ -Fe, 84.6 pct α -Fe, and 12 pct M 7 C 3 carbides. The dilatometric analysis showed that the transformation of metastable austenite into martensite took place during cooling from 828 K (555 °C). The additional annealing at 523 K (250 °C) for 2 hours after heat treatment at 828 K (555 °C) caused the precipitation of carbides from the martensite. After tempering at 903 K (630 °C), the thixo-cast microstructure showed globular grains consisting mainly of thick lamellar perlite of the average hardness 555 HV 0.02 . Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-012-1347-6 Authors Łukasz Rogal, Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, Krakow, 30-059 Poland Jan Dutkiewicz, Institute of Metallurgy and Materials Science of the Polish Academy of Sciences, Krakow, 30-059 Poland Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    This study investigated the influence of the duration of milling on the formation of TiC-reinforced iron composite through carbothermal reduction of a hematite and anatase mixture. Mixtures of hematite, anatase, and graphite powders were mechanically activated in a planetary ball mill in an argon atmosphere with different milling times (0 to 60 hours). X-ray diffraction showed that with increasing milling time, the crystallite size of the hematite decreased to nanometer range, accompanied by an increment in internal strain. Prolonging the milling process increased dislocation density of the as-milled powder. The as-milled powder was consolidated by cold pressing under 100 MPa and sintered in vacuum at 1373 K (1100 °C). High temperature during sintering resulted in the formation of iron and titanium carbide phases as confirmed by X-ray diffraction, scanning electron microscope, and energy dispersive X-ray analysis. Without mechanically activated milling, the reaction forming TiC did not occur during sintering at 1373 K (1100 °C), indicating a reduction in reaction temperature promoted by mechanical milling. An increase in milling time resulted in an increase in sintered density and hardness due to the fineness of the composite powder, together with complete TiC and iron phase formation. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1440-x Authors Hussain Zuhailawati, School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia Mohd Salihin Hassin, School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, Engineering Campus, 14300 Nibong Tebal, Penang, Malaysia Samayamutthirian Palaniandy, JKMRC University of Queensland, 40 Isles Road, Indooroopilly, QLD 4068, Australia Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Admixing pure elements to powder mixes can cause the formation of heterogeneous microstructures in sintered parts. For instance, nickel is renowned for forming nickel-rich areas (NRA) in powder metallurgy (PM) nickel steels due to its poor diffusivity in iron matrix (or lattice). The present work is aimed at characterizing the principal diffusion mechanisms of nickel and their influence on microstructures and properties of PM nickel steels. A new wavelength dispersive X-ray spectrometry (WDS) approach linking line scans and X-ray maps to concentration maps is proposed. Grain boundary and volume diffusion coefficients of admixed nickel have been determined in PM nickel steels using Suzuoka’s equation. Results also show that nickel distributes itself in the iron matrix mainly by surface and grain boundary diffusion. Content Type Journal Article Pages 1-12 DOI 10.1007/s11661-012-1417-9 Authors Bernard Tougas, Department of Mining, Metallurgical and Materials Engineering, Université Laval, 1065 De la Médecine, Quebec, QC G1V 0A6, Canada Carl Blais, Department of Mining, Metallurgical and Materials Engineering, Université Laval, 1065 De la Médecine, Quebec, QC G1V 0A6, Canada François Chagnon, Rio Tinto Metal Powders, 1655 rte Marie-Victorin, Sorel-Tracy, QC J3R 4R4, Canada Sylvain Pelletier, National Research Council of Canada, 75 boul. de Mortagne, Boucherville, QC J4B 6Y4, Canada Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    There is a growing demand for single-use disposable polymer devices with features at submicron scales. This requires resilient tooling which can be patterned to scales of the order of hundreds of nanometers. The requisite topology can be imparted to silicon, but it is too brittle to be of use in a die to mold thousands of plastic parts. The polycrystalline nature of tool steel means that it cannot be patterned with submicron detail. Some bulk amorphous alloys have the requisite mechanical properties to be viable as materials for such dies, and can be patterned— e.g. , via embossing as a supercooled liquid into MEMS silicon or using focused ion beam (FIB)—with submicron features which may persevere over many thousands of molding cycles. The composition of the amorphous alloy must be carefully selected to suit the particular molding application (polymer/process). The state-of-the-art methodology is presented, along with results of our recent experimental investigations. Content Type Journal Article Category Symposium: Bulk Metallic Glasses IX Pages 1-10 DOI 10.1007/s11661-012-1427-7 Authors David J. Browne, School of Mechanical & Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland Dermot Stratton, School of Mechanical & Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland Michael D. Gilchrist, School of Mechanical & Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland Cormac J. Byrne, School of Mechanical & Materials Engineering, University College Dublin, Belfield, Dublin 4, Ireland Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The ethylene glycol-1,4-dioxane system is studied by means of differential scanning calorimetry over a wide range of temperatures (−90 to 25°C) and is found to be a simple eutectic with the eutectic point at 10 mol % of dioxane (−16.5°C). Unlike a water-dioxane system, in which the clathrate with dioxane: H 2 O = 1: 34 ratio is formed, the observed phase diagram showed no evidence of clathrate formation, due presumably to its hydrogen bond geometry and the intermolecular interaction properties of ethylene glycol. Content Type Journal Article Category Short Communications Pages 1745-1746 DOI 10.1134/S0036024412110234 Authors M. N. Rodnikova, Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia I. A. Solonina, Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia M. R. Kiselev, Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, 119071 Russia S. V. Makaev, Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow, 119991 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    The solubility of atmospheric oxygen in solutions of surfactants of different natures at 293 K and pH 8 is determined by gas chromatography. It is found that additives of nonionic surfactants decrease the oxygen content in the solution in the premicellar region and increase its solubility in the micellar region. It is shown that, for anionic surfactants, a decrease in the solubility of O 2 is observed over the entire concentration range. Content Type Journal Article Category Short Communications Pages 1753-1755 DOI 10.1134/S0036024412110088 Authors G. V. Chistyakova, Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, 153045 Russia S. A. Koksharov, Krestov Institute of Solution Chemistry, Russian Academy of Sciences, Ivanovo, 153045 Russia T. V. Vladimirova, Ivenergo, Ivanovo, 153326 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    It was shown that after partial dehydration occurs a simultaneous condensation of four mol of initial monomer Gd(NO 3 ) 3 · 6H 2 O into a tetramer Gd 4 O 4 (NO 3 ) 4 . The heterocycle containing 4 gadolinium atoms gradually loses N 2 O 5 and, through the formation of unstable oxynitrates, is transformed into Gd 2 O 3 . The interatomic distances and angles were calculated using the molecular mechanics method. The comparison of the potential energies of consecutive oxyphosphates permitted an evaluation of their stability. The models of intermediate oxynitrates represent a reasonably good approximation to the real structures and a proper interpretation of experimental data. Content Type Journal Article Category Chemical Kinetics and Catalysis Pages 1659-1663 DOI 10.1134/S0036024412110180 Authors P. P. Melnikov, Federal University of Mato Grosso do Sul/UFMS, Caixa Postal 549, Campo Grande/MS, Brazil V. A. Nascimento, Federal University of Mato Grosso do Sul/UFMS, Caixa Postal 549, Campo Grande/MS, Brazil L. Z. Zanoni Consolo, Federal University of Mato Grosso do Sul/UFMS, Caixa Postal 549, Campo Grande/MS, Brazil Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    A dimensionless complex containing the surface free energy of a crystal-liquid interface γ, and the entropy jump, temperature, and density of a crystal phase is described using the phenomenology of thermodynamic similarity; this complex remains constant at the melting line. It is demonstrated that the complex refines the result obtained by Skripov and Faizullin in [6] and enables us to estimate the temperature dependence of γ. Our calculations show that the surface free energy of the crystal-liquid interface of normally melting compounds is a monotonically increasing function of temperature. Content Type Journal Article Category Short Communications Pages 1763-1765 DOI 10.1134/S0036024412110040 Authors V. G. Baidakov, Institute of Thermal Physics, Ural Branch, Russian Academy of Sciences, Yekaterinburg, 620016 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    Thermodynamic parameters are determined for the adsorption of vapors of hydrocarbons and polar compounds of different structure on carbon adsorbent modified by a monomolecular layer of heptakis (2,3,6-tri- O -benzoyl)-β-cyclodextrin. The effect of the structure and polarity of organic compounds on adsorption onto an adsorbent support with a chiral macrocyclic modifier are considered. Content Type Journal Article Category Short Communications Pages 1769-1772 DOI 10.1134/S0036024412110155 Authors K. A. Kopytin, Samara State University, Samara, 443011 Russia S. Yu. Kudryashov, Samara State University, Samara, 443011 Russia N. G. Gerasimova, Samara State University, Samara, 443011 Russia L. A. Onuchak, Samara State University, Samara, 443011 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    A thermodynamic variation of the Lindemann criterion for the vaporization of metals is proposed. It is shown that the critical amplitude of vibrations of atoms at the boiling point averages 1.42 bond lengths. Close values of interatomic distances result from the Vinet universal equation for the atomization of metals under the action of high temperatures (1.48) and negative pressures (1.50). The last value corresponds to the Van der Waals distances between metal atoms. Content Type Journal Article Category Short Communications Pages 1759-1762 DOI 10.1134/S0036024412110052 Authors S. S. Batsanov, Institute of Structural Macrokinetics and Problems of Materials Science, Russian Academy of Sciences, Chernogolovka, Moscow oblast, 142432 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    Samples of composite nanomaterials obtained by the thermal treatment of mixtures of MoO 3 nano-dispersed powder and ultrafine powder of Mo with precipitate from removing iron from groundwater are studied by means of X-ray diffraction and infrared spectroscopy. The structure of these samples (phase composition, average crystallite size, microdistortions (microstresses) of their crystal lattices, and certain texture parameters) are determined. It is suggested that under certain conditions, shells from the nanoparticles of Mo and/or MoO 3 are formed on the surface of sediment particles, preventing the identification of iron-containing phases. Estimates are made of the sorption activity of some materials with respect to carbon monoxide (CO). Content Type Journal Article Category Physical Chemistry of Nanoclusters and Nanomaterials Pages 1689-1696 DOI 10.1134/S0036024412110210 Authors L. Yu. Novoselova, Institute of Petroleum Chemistry, Siberian Branch, Russian Academy of Sciences, Tomsk, 634021 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    A table for determining the first derivatives of thermodynamic parameters is proposed. The table differs from the familiar Suvorov table in that the five dimension parameters are replaced with four dimensionless thermodynamic parameters. Content Type Journal Article Category Short Communications Pages 1747-1750 DOI 10.1134/S003602441211009X Authors V. P. Dobrodeev, Rybinsk State Aviation Technological Academy, Rybinsk, 152934 Russia N. A. Kalyaeva, Rybinsk State Aviation Technological Academy, Rybinsk, 152934 Russia A. V. Dobrodeev, Rybinsk State Aviation Technological Academy, Rybinsk, 152934 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    The conjugated diffusion transport of amino acid and mineral salt through a profiled sulfo group cation exchange membrane that simulates the extraction of amino acid from wash waters of microbiological production containing mineral components not used in synthesis is studied. The competitive nature of the conjugation of flows resulting in a decrease in the rate of the mass transfer of components and their separation factor is established from a comparative analysis of experimental data on the diffusion transfer of phenylalanine and sodium chloride in the form of hydrogen from individual and mixed solutions through a profiled sulfo group cation exchange membrane. The range of concentrations and the ratio of components in solution corresponding to the effective separation of phenylalanine and sodium chloride are determined. Content Type Journal Article Category Physical Chemistry of Separation Processes: Chromatography Pages 1726-1731 DOI 10.1134/S0036024412110271 Authors V. I. Vasil’eva, Voronezh State University, Voronezh, 394006 Russia E. A. Vorob’eva, Voronezh State University, Voronezh, 394006 Russia Journal Russian Journal of Physical Chemistry A, Focus on Chemistry Online ISSN 1531-863X Print ISSN 0036-0244 Journal Volume Volume 86 Journal Issue Volume 86, Number 11

Description:    A centrifugally cast 20Cr32Ni1Nb stainless steel manifold in service for 16 years at temperatures ranging from 1073 K to 1123 K (800 °C to 850 °C) has been characterized using scanning electron microscopy (SEM), electron probe micro-analysis (EPMA), auger electron spectroscopy (AES), and X-ray diffraction (XRD). Nb(C,N), M 23 C 6 , and the silicide G-phases (Ni 16 Nb 6 Si 7 ) were all identified in a conventional SEM, while the nitride Z-phase (CrNbN) was observed only in AES. M 23 C 6 , Z-phase and G-phase were characterized in XRD. Thermodynamic equilibrium calculations using ThermoCalc Version S, with the TCS Steel and Fe-alloys Database (TCFE6), and Thermotech Ni-based Superalloys Database (TTNI8) were validated by comparing experimental phase fraction results obtained from both EPMA and AES. A computational study looking at variations in the chemical composition of the alloy, and how they affect phase equilibria, was investigated. Increasing the nitrogen concentration is shown to decrease G-phase formation, where it is replaced by other intermetallic phases such as Z-phase and π -phase that do not experience liquation during pre-weld annealing treatments. Suppressing G-phase formation was ultimately determined to be a function of minimizing silicon content, and understabilizing the Nb/(C + 6/7N) ratio. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1457-1 Authors Matthew P. Dewar, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB T6G 2V4, Canada Adrian P. Gerlich, University of Waterloo, Waterloo, ON, Canada Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    W-5.6Ni-1.4Fe heavy alloys were prepared by the method of spark-plasma sintering, and the densification and grain growth kinetics were analyzed as a function of various parameters such as sintering temperature and dwell duration. It is found that the local temperature gradient at the vicinity of the pores can cause the matrix phase melting or softening, resulting in a viscous layer coating the W particles and an improved solubility of W into the matrix phase. In the initial stage, particle rearrangement and neck formation and growth take place, and γ -(Ni, Fe) matrix phase has formed. Dissolution-precipitation and Ni-enhanced W grain boundary diffusion together with viscous process contribute to the simultaneous densification and grain growth in the intermediate stage. During the final stage, fast grain growth, controlled by both gas-phase diffusion and dissolution-precipitation mechanisms, dominates over the densification. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1454-4 Authors Ke Hu, National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou, 510640 P.R. China Xiaoqiang Li, National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou, 510640 P.R. China Shengguan Qu, National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou, 510640 P.R. China Yuanyuan Li, National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology, Guangzhou, 510640 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Damage tolerance (toughness and plasticity) properties of a ZrCuNiAl bulk metallic glass (BMG) are tailored through Sn alloying under ambient conditions. The result shows that the measured fracture energy is clearly correlated with the product ( R ) of Young’s modulus and averaged size of vein patterns on mode I crack surfaces of these BMGs. The implications of the current result on other BMGs are also briefly discussed, which might be useful for the evaluation of damage tolerance of tough BMGs. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1453-5 Authors C. C. Yuan, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 P.R. China X. X. Xia, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 P.R. China K. H. Jiang, School of Mechanics, Beihang University, Beijing, P.R. China D. Q. Zhao, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 P.R. China X. K. Xi, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    In this study, a comparison in the oxidation and corrosion behavior of Ni/Ni-Co aluminum and alumina-reinforced electrodeposited composites has been made. The developed coatings were characterized for the morphology, structure, microhardness, oxidation, and corrosion resistance. It was found that the incorporation of Al particles in NiCo matrix is higher (9 wt pct) compared to Ni matrix (1 wt pct). In the case of aluminum oxide particles, about 5 and 7 wt pct had been obtained in Ni and NiCo matrices respectively. The difference in the surface morphology was observed with respect to metallic (Al) and inert ceramic (Al 2 O 3 ) particle incorporation. X-ray diffraction studies showed the presence of predominant Ni (200) reflection in the coatings. Also, peaks corresponding to Al and Al 2 O 3 particles were present. The Ni/NiCo-Al coatings exhibited higher microhardness values at 1273 K (1000 °C) compared to alumina-reinforced coatings, indicating better thermal stability of the former coatings. The NiAl coating showed one and two orders of magnitude improved oxidation resistance compared to NiCoAl and Ni/NiCo-Al 2 O 3 coatings, respectively. It was observed that the Ni-Al composite coating exhibited poor corrosion resistance in 3.5 pct NaCl solution compared to the other coatings studied. Content Type Journal Article Pages 1-12 DOI 10.1007/s11661-012-1452-6 Authors Meenu Srivastava, Council of Scientific and Industrial Research, Surface Engineering Division, National Aerospace Laboratories, Bangalore, 560 017 India J. N. Balaraju, Council of Scientific and Industrial Research, Surface Engineering Division, National Aerospace Laboratories, Bangalore, 560 017 India B. Ravisankar, Department of Metallurgical and Materials Engineering, National Institute of Technology, Tiruchirappalli, 620015 TN, India V. K. William Grips, Council of Scientific and Industrial Research, Surface Engineering Division, National Aerospace Laboratories, Bangalore, 560 017 India Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Homo–Ge, homo–Si, and hetero–Si 0.2 Ge 0.8 alloy epitaxial layers, using molecular beam epitaxy (MBE), were grown on Ge and Si (001) substrates in order to study development of crystalline strains caused by ion bombardment during the growth of materials. Ion energies and ion/atom fluxes were used in the epitaxial growth, and significant lattice distortions along the growth direction developed. Using high-resolution X-ray diffraction (HRXRD) and high-resolution transmission electron microscopy (HRTEM), the form of distortion, caused by low-energy argon (Ar + ) and xenon (Xe + ) bombardment of the thin epitaxial films grown on the (001) substrates, were investigated. The isotropic point defects case (of spherical distortions) occurs in epitaxial thin films “as-grown” processes. The intensity distribution has two maxima, one from the distorted layer and the other from the original unaffected matrix. The significant changes in the 2θ location, peak broadening and integrated intensity from the secondary (004)* reflections were obtained as a function of aging temperatures in the grown layers. Defects-induced diffuse scattering close to and between Bragg reflections supplies information on the strain and symmetry of the distortions fields and yields the atomic structure of point defects (self-interstitial, vacancies, and small clusters). First, aging heat treatment affects the distribution of distortions obtained in local regions at the “as-grown” layer, which develops to a special topography of continued distortions at higher aging temperatures. At aging temperatures above 923 K (650 °C), this extra diffraction peak disappears. The TEM observations reveal the appearance of dislocation lines with dark and bright contrasts around them, interdislocation strain contrasts, and disordered point defects atoms in the silicon region with semicoherent interfaces. The ion bombardment-induced formations and injection of the different types of pointlike defects and defects clusters. Content Type Journal Article Category Symposium: Neutron and X-Ray Studies of Advanced Materials V Pages 1-13 DOI 10.1007/s11661-012-1448-2 Authors Paul Rozenak, Hydrogen Energy Batteries Ltd., Omer, 84965 Israel Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    In this article, a genetic algorithm (GA) is used to predict the mechanical properties and to optimize the process conditions of Al nanocomposites. An artificial intelligence method is also implemented as an assisting tool for engineering tasks of GAs. The principle of the survival of the fittest is applied to produce successively superior approximations to a solution. A population of points at each iteration is generated. The population approaches an optimal solution. The next population by computations that involve random choices is selected. The optimal volume percentage of SiC, cooling rate, and temperature gradient are computed to be 2.84 pct, 283 K/s (10 °C/s), 1273 K/m (1000 °C/m), respectively. Content Type Journal Article Pages 1-7 DOI 10.1007/s11661-012-1339-6 Authors Ali Mazahery, Karaj Branch, Islamic Azad University, Karaj, Iran Mohsen Ostad Shabani, Karaj Branch, Islamic Azad University, Karaj, Iran Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    We developed a novel process for foaming aluminum and its alloys without using a blowing agent. The process involves a designated apparatus in which molten aluminum and its alloys are first foamed under reduced pressure and then solidified quickly. Foaming was done for pure aluminum (99.99 pct) and AlMg5 alloy not containing stabilizing particles and AlMg5 and AlSi9Mg5 alloys containing 5 vol pct SiO 2 particles. We discuss the foaming mechanism and develop a model for estimating the porosity that can be achieved in this process. The nucleation of pores in foams is also discussed. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1398-8 Authors G. S. Vinod Kumar, Technische Universität Berlin, 10623 Berlin, Germany M. Mukherjee, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, India F. Garcia-Moreno, Institute of Applied Materials (Fl1), Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany J. Banhart, Institute of Applied Materials (Fl1), Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The surface hardness of powder injection molded (PIM) 316L is generally low due to the inherited austenitic structure and large grains induced during high-temperature sintering. To increase the surface hardness and the wear resistance, low-temperature carburization (LTC) was applied to PIM 316L. With carburization at 773 K (500 °C) for 24 hours, the resulting hardness at the surface increases from 160 to 810 HV due to the “colossal” supersaturation of interstitial carbon and M 5 C 2 carbide, and the corrosion resistance is not deteriorated. The carburized depth is about 40 μm, and the carbon content in this layer is about 3.25 wt pct or 13.5 at. pct, which causes lattice expansion of the austenite. When the carburization temperature increases to 823 K (550 °C), or the carburization time increases to 72 hours, chromium carbides are observed and the corrosion resistance is impaired. One distinct advantage of applying LTC to PIM 316L is that no acid cleaning process is required, unlike for wrought counterparts, because of the clean surface of the sintered materials. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1458-0 Authors Li-Hui Cheng, Department of Materials Science and Engineering, National Taiwan University, 1 Roosevelt Road, Sec. 4, Taipei, 106 Taiwan, ROC Kuen-Shyang Hwang, Department of Materials Science and Engineering, National Taiwan University, 1 Roosevelt Road, Sec. 4, Taipei, 106 Taiwan, ROC Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The investment casting process is an economic production method for engineering components in TiAl-based alloys and offers the benefits of a near net-shaped component with a good surface finish. An investigation was undertaken to develop three new face coat systems based on yttria, but with better sintering properties. These face coat systems were mainly based on an yttria-alumina-zirconia system (Y 2 O 3 -0.5 wt pct Al 2 O 3 -0.5 wt pct ZrO 2 ), an yttria-fluoride system (Y 2 O 3 -0.15 wt pct YF 3 ), and an yttria-boride system (Y 2 O 3 -0.15 wt pct B 2 O 3 ). After sintering, the chemical inertness of the face coat was first tested and analyzed using a sessile drop test through the metal wetting behavioral change for each face coat surface. Then, the interactions between the shell and metal were studied by centrifugal investment casting TiAl bars. Although the sintering aids in yttria can decrease the chemical inertness of the face coat, the thickness of the interaction layer in the casting was less than 10  μ m; therefore, these face coats still can be possible face coat materials for investment casting TiAl alloys. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1455-3 Authors Xu Cheng, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT U.K. Chen Yuan, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT U.K. Nick Green, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT U.K. Paul Withey, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT U.K. Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The creep rates of AA1100 are measured during exposure to a variety of aggressive environments. NaCl solutions of various concentrations have no influence on the steady-state creep behavior, producing creep rates comparable to those measured in lab air at room temperature. However, after an initial incubation period of steady strain rate, a dramatic increase of strain rate is observed on exposure to HCl solutions and NaOH solutions, as well as during cathodic polarization of specimens in NaCl solutions. Creep strain produces a continuous deformation and elongation of the sample surface that is comparable to slow strain rates at crack tips thought to control the kinetics of crack growth during stress corrosion cracking (SCC). In this experiment, we separate the strain and surface deformation from the complex geometry of the crack tip to better understand the processes at work. Based on this concept, two possible explanations for the environmental influences on creep strain rates are discussed relating to the anodic dissolution of the free surface and hydrogen influences on deformation mechanisms. Consistencies of pH dependence between corrosion creep and SCC at low pH prove a creep-involved SCC mechanism, while the discrepancies between corrosion creep behavior and previous SCC results at high pH indicate a rate-limit step change in the crack propagation of the SCC process. Content Type Journal Article Category Symposium: Environmental Damage in Structural Materials under Static/Dynamic Loads at Ambient Temperature Pages 1-9 DOI 10.1007/s11661-012-1294-2 Authors Quanhe Wan, Mechanical Engineering Department, University of Rochester, Rochester, NY 14642, USA David J. Quesnel, Mechanical Engineering Department, University of Rochester, Rochester, NY 14642, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Acoustic emission (AE) is used in this article to study melting and solidification of embedded indium particles in the size ranging from 0.2 to 3  μ m in diameter and to show that dislocation generation occurs in the aluminum matrix to accommodate a 2.5 pct volume change. The volume-averaged acoustic energy produced by indium particle melting is similar to that reported for bainite formation upon continuous cooling. A mechanism of prismatic loop generation is proposed to accommodate the volume change, and an upper limit to the geometrically necessary increase in dislocation density is calculated as 4.1 × 10 9  cm −2  for the Al-17In alloy. Thermomechanical processing is also used to change the size and distribution of the indium particles within the aluminum matrix. Dislocation generation with accompanied AE occurs when the melting indium particles are associated with grain boundaries or upon solidification where the solid-liquid interfaces act as free surfaces to facilitate dislocation generation. AE is not observed for indium particles that require super heating and exhibit elevated melting temperatures. The AE work corroborates previously proposed relaxation mechanisms from prior internal friction studies and that the superheat observed for melting of these micron-sized particles is a result of matrix constraint. Content Type Journal Article Category Symposium: Atomistic Effects in Migrating Interphase Interfaces: Recent Progress and Future Study Pages 1-12 DOI 10.1007/s11661-012-1468-y Authors Michael M. Kuba, Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409-0330, USA David C. Van Aken, Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409-0330, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Microwave dielectric ceramics of Ba[Zn (1− x )/3 Ni x /3 Nb 2/3 ]O 3 (BZNN, x  = 0.0, 0.5, 0.6, 0.7, 0.8) were sintered at 1773 K (1500 °C) for 3 hours by the conventional solid-state reaction method. To clarify the relationship between dielectric properties and crystal structures, vibration spectra (Raman spectroscopy and Fourier transform far-infrared reflection spectroscopy (FTIR)) and X-ray diffraction (XRD) were employed to study Ba[Zn (1-x)/3 Ni x/3 Nb 2/3 ]O 3 solid solutions. Crystal structures were determined as cubic perovskite structures, and no phase transition appears in substitution of Ni 2+ to Zn 2+ ions. Raman spectroscopy was used to discuss the correlation of dielectric properties with Raman shifts and full-width at half-maximum (FWHM) values, which indicate that dielectric properties are closely related to both FWHM values and A 1g (Nb) mode shifts. FTIR spectra and imaginary parts of dielectric constants were calculated to obtain the correlation between polar phonon modes and dielectric properties with Ni 2+ concentration. Content Type Journal Article Pages 1-7 DOI 10.1007/s11661-012-1401-4 Authors Feng Shi, College of Physics and Electronics, Shandong Normal University, Jinan, 250014 People’s Republic of China Chuanling Diao, College of Physics and Electronics, Shandong Normal University, Jinan, 250014 People’s Republic of China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The solidification structures of Al-Cu 206 cast alloys at a high iron level of 0.5 pct were systematically studied by means of differential scanning calorimetry, electron backscattered diffraction, and transmission electron microscopy. The full solidification sequences of the 206 cast alloys at 0.5 pct Fe were established. The influences of both alloy composition ( i.e. , Si and Mn contents) and cooling rate on the formation and phase selection of the iron-rich intermetallics have been systematically explored. At a cooling rate of 12 K/min, it was found that one of the three iron-rich phases, i.e. , Chinese script Al m (FeMn) and α-Fe, or platelet Al 3 (FeMn), may precipitate as the dominant iron-rich intermetallic, depending on Si and Mn contents. However, the dominant Chinese script iron-rich intermetallics, Al m (FeMn) and/or α-Fe, can be fully obtained for the 206 Al-Cu cast alloys at 0.5 pct Fe above a threshold cooling rate that can easily be obtained in normal industrial casting conditions, indicating that there is a significant potential of designing and developing new 206 Al-Cu cast alloys with a high tolerant iron content. Content Type Journal Article Pages 1-14 DOI 10.1007/s11661-012-1419-7 Authors K. Liu, University of Québec at Chicoutimi, Chicoutimi, QC G7H 2B1, Canada X. Cao, University of Québec at Chicoutimi, Chicoutimi, QC G7H 2B1, Canada X.-G. Chen, University of Québec at Chicoutimi, Chicoutimi, QC G7H 2B1, Canada Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The flow behavior and recrystallization response of a 9310 steel alloy deformed in the ferrite temperature range were studied in this work. Samples were compressed under various conditions of strain (0.6, 0.8 and multi-axial), strain rate (10 −4  seconds −1 to 10 −1  seconds −1 ) and temperature [811 K to 1033 K (538 °C to 760 °C)] using a Gleeble thermo-mechanical simulator. Deformation was characterized by both qualitative and quantitative means, using standard microscopy, electron backscatter diffraction (EBSD) analysis and flow stress modeling. The results indicate that deformation is primarily accommodated through dynamic recovery in sub-grain formation. EBSD analysis shows a continuous increase in sub-grain boundary misorientation with increasing strain, ultimately producing recrystallized grains from the sub-grains at high strains. This suggests that a sub-grain rotation recrystallization mechanism predominates in this temperature range. Analyses of the results reveal a decreasing mean dynamically recrystallized grain size with increasing Zener-Hollomon parameter, and an increasing recrystallized fraction with increasing strain. Content Type Journal Article Pages 1-15 DOI 10.1007/s11661-012-1381-4 Authors David Snyder, Illinois Institute of Technology, 10 W. 32nd St., Chicago, IL 60616, USA Edward Y. Chen, Transition45 Technologies, Inc., 1739 N. Case St., Orange, CA 92865, USA Charlie C. Chen, Transition45 Technologies, Inc., 1739 N. Case St., Orange, CA 92865, USA Sammy Tin, Illinois Institute of Technology, 10 W. 32nd St., Chicago, IL 60616, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The Mg 17 Ni 1.5 Ce 0.5 hydrogen storage composites with different contents of graphite were prepared by a new method of mechanical milling and subsequent microwave sintering. The small particle size (~25  μ m) and the low echo ratio of power indicate that graphite plays an important role not only as a lubricant during mechanical milling but also as a supplementary heating material during microwave sintering. As a catalyst in the hydriding/dehydriding (H/D) reaction, graphite also improved the hydrogen storage properties of the composites. The hydrogen absorption and desorption capacities of Mg 17 Ni 1.5 Ce 0.5 with 5 wt pct graphite were 5.34 and 5.30 wt pct H 2 at 573 K (300 °C), its onset temperature of dehydriding reaction was 511 K (238 °C), and its activation energies of H/D reaction were 40.9 and 54.5 kJ/mol H 2 , respectively. The kinetic mechanisms of the H/D reaction are also discussed. Content Type Journal Article Category Symposium: Neutron and X-Ray Studies of Advanced Materials V Pages 1-10 DOI 10.1007/s11661-012-1301-7 Authors Jie Meng, Shanghai Key Laboratory of Modern Metallurgy & Materials Processing, Shanghai University, Shanghai, 200072 People’s Republic of China Xun-Li Wang, Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA Kuo-Chih Chou, Shanghai Key Laboratory of Modern Metallurgy & Materials Processing, Shanghai University, Shanghai, 200072 People’s Republic of China Qian Li, Shanghai Key Laboratory of Modern Metallurgy & Materials Processing, Shanghai University, Shanghai, 200072 People’s Republic of China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The evolution of titanium powders in the pure aluminum melt at a lower temperature was studied in our research. The process involved some titanium powders being added into the pure aluminum melt at 1003 K (730 °C), and then the melt was cast into an ingot after 5 minutes. A reaction layer composed of some loose Al 3 Ti particles was formed on the solid Ti surface due to the reactive diffusion between titanium and aluminum. In-situ blocky Al 3 Ti particles smaller than 5  μ m were produced in the aluminum matrix. A reaction-peeling model was suggested to illustrate the formation mechanism of Al 3 Ti particles, and a simple approach for fabricating in-situ Al 3 Ti/Al-alloy composites was proposed as well. Content Type Journal Article Category Communication Pages 1-4 DOI 10.1007/s11661-012-1326-y Authors Z. W. Liu, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240 P.R. China Q. Han, Department of Mechanical Engineering Technology, Purdue University, West Lafayette, IN 47906, USA J. G. Li, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The diffusionless growth model of bainite formation was included in an international consensus in 1912 that all transformation products of austenite form by an initial transformation to martensite. The introduction of isothermal treatment revealed that all the products form directly. However, for bainite, the idea of some relation to martensite survived and developed into the diffusionless paradigm. Zener introduced the T o concept for predicting the start temperature of lower bainite, but also described diffusional growth of upper bainite. The present description of the diffusionless growth model is now examined and criticized. Content Type Journal Article Pages 1-9 DOI 10.1007/s11661-012-1263-9 Authors M. Hillert, Department of Materials Science and Engineering, KTH Royal Institute of Technology, 10044 Stockholm, Sweden A. Borgenstam, Department of Materials Science and Engineering, KTH Royal Institute of Technology, 10044 Stockholm, Sweden Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A developed Ti-35 pct Nb-2.5 pct Sn (wt pct) alloy was synthesized by mechanical alloying using high-energy ball-milled powders, and the powder consolidation was done by pulsed current activated sintering (PCAS). The starting powder materials were mixed for 24 hours and then milled by high-energy ball milling (HEBM) for 1, 4, and 12 hours. The bulk solid samples were fabricated by PCAS at 1073 K to 1373 K (800 °C to 1100 °C) for a short time, followed by rapid cooling to 773 K (500 °C). The relative density of the sintered samples was about 93 pct. The Ti was completely transformed from α to β -Ti phase after milling for 12 hours in powder state, and the specimen sintered at 1546 K (1273 °C) was almost transformed to β -Ti phase. The homogeneity of the sintered specimen increased with increasing milling time and sintering temperature, as did its hardness, reaching 400 HV after 12 hours of milling. The Young’s modulus was almost constant for all sintered Ti-35 pct Nb-2.5 pct Sn specimens at different milling times. The Young’s modulus was low (63.55 to 65.3 GPa) compared to that of the standard alloy of Ti-6Al-4V (100 GPa). The wear resistance of the sintered specimen increased with increasing milling time. The 12-hour milled powder exhibited the best wear resistance. Content Type Journal Article Pages 1-9 DOI 10.1007/s11661-012-1298-y Authors Abdel-Nasser Omran, Mining and Metallurgical Department, Faculty of Engineering, Al-Azhar University, Qena, Egypt Kee-Do Woo, Division of Advanced Materials Engineering & RCAMD, Chonbuk National University, Jeonju, 561-756 Korea Hyun Bom Lee, Mg Flat Product Process Engineering Team, POSCO, Jeonnam, 540-856 Korea Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A two-camera Particle Image Velocimetry (PIV) technique is applied to study the flow pattern and the equiaxed crystal motion during an equiaxed/columnar solidification process of Ammonium Chloride in a die cast cell. This technique is able to measure simultaneously the liquid and the equiaxed grain velocity pattern as already shown in Part I of this paper. The interaction between the equiaxed grains and the melt flow was explored by means of relative velocities. In single isolated configurations, the settling velocity of equiaxed crystal was found to be 41 times smaller than spheres of equivalent size. The coupling between the fluid flow and the equiaxed crystals was found to be important in areas of high crystal density. Chaotic and turbulent behaviors are found to be damped in regions of high equiaxed crystal density. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1415-y Authors Abdellah Kharicha, Department of Metallurgy, University of Leoben, Leoben, Austria Mihaela Stefan-Kharicha, Department of Metallurgy, University of Leoben, Leoben, Austria Andreas Ludwig, Department of Metallurgy, University of Leoben, Leoben, Austria Menghuai Wu, Department of Metallurgy, University of Leoben, Leoben, Austria Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The effect of C fraction (C/N) on stacking fault energy (SFE) of austenitic Fe-18Cr-10Mn steels with a fixed amount of C + N (0.6 wt pct) was investigated by means of neutron diffraction and transmission electron microscopy (TEM). The SFE were evaluated by the Rietveld whole-profile fitting combined with the double-Voigt size-strain analysis for neutron diffraction profiles using neutron diffraction. The measured SFE showed distinguishable difference and were well correlated with the change in deformation microstructure. Three-dimensional linear regression analyses yielded the relation reflecting the contribution of both C + N and C/N: SFE (mJ/m 2 ) = –5.97 + 39.94(wt pct C + N) + 3.81(C/N). As C fraction increased, the strain-induced γ → ε martensitic transformation was suppressed, and deformation twinning became the primary mode of plastic deformation. Content Type Journal Article Category Communication Pages 1-5 DOI 10.1007/s11661-012-1423-y Authors Tae-Ho Lee, Ferroy Alloy Department, Korea Institute of Materials Science, Changwon, 642-831 South Korea Heon-Young Ha, Ferroy Alloy Department, Korea Institute of Materials Science, Changwon, 642-831 South Korea Byoungchul Hwang, Ferroy Alloy Department, Korea Institute of Materials Science, Changwon, 642-831 South Korea Sung-Joon Kim, Graduate Institute of Ferrous Technology, Pohang University of Science & Technology, Pohang, 790-784 South Korea Eunjoo Shin, Neutron Physics Department, Korea Atomic Energy Research Institute, Daejeon, 305-600 South Korea Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A dual phase particle image velocimetry technique is applied to study the flow pattern during a combined equiaxed-columnar solidification process. This technique is able to measure simultaneously the liquid and the equiaxed grain velocity pattern within an academic Ammonium Chloride water ingot. After the formation of a steady convection pattern, solutal buoyancy together with falling crystals destabilize and break the steady convection flow into multiple chaotic cells. In the beginning of the solidification process, the flow transitioned from 2D to a 3D turbulent regime. The kinetic energy for the flow was calculated during the solidification process. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1414-z Authors Abdellah Kharicha, Department of Metallurgy, University of Leoben, Leoben, Austria Mihaela Stefan-Kharicha, Department of Metallurgy, University of Leoben, Leoben, Austria Andreas Ludwig, Department of Metallurgy, University of Leoben, Leoben, Austria Menghuai Wu, Department of Metallurgy, University of Leoben, Leoben, Austria Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The precipitates in as-cast and heat-treated biomedical Co-28Cr-6Mo-(0 to 0.35)C-(0.15 to 0.25)N alloys (mass pct) were investigated. Heat treatment was carried out at temperatures of 1473 K to 1573 K (1200 °C to 1300 °C) for holding periods of 0 to 43.2 ks. In the as-cast and heat-treated Co-Cr-Mo-N alloys, no precipitates were detected; nitrogen effectively inhibited the formation of the σ-phase and stabilized the face-centered cubic (fcc) metallic γ-phase. The precipitates observed in the as-cast and heat-treated Co-Cr-Mo-C-N alloys were of the M 23 X 6 type, M 2 X type, π-phase (M 2 T 3 X type with a β-Mn structure), and η-phase (M 6 X-M 12 X type). Complete precipitate dissolution was detected in the alloys with carbon contents of less than 0.3 mass pct regardless of the nitrogen content. The main precipitates were of the M 2 X and M 23 X 6 types after heat treatment for 1.8 to 43.2 ks. The π-phase precipitate was detected in the early stage of heat treatment at high temperatures. The formation of the M 2 X-type precipitate was enhanced by the addition of nitrogen, although the constitution of the precipitates depended on the balance between the nitrogen and carbon contents and the heat-treatment conditions. Content Type Journal Article Pages 1-10 DOI 10.1007/s11661-012-1399-7 Authors Shingo Mineta, Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-6-02, Aza Aoba, Aramaki, Aoba-ku, Sendai, 980-8579 Japan Alfirano, Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-6-02, Aza Aoba, Aramaki, Aoba-ku, Sendai, 980-8579 Japan Shigenobu Namba, Materials Research Laboratory, Kobe Steel, Ltd., Kobe, 651-2271 Japan Takashi Yoneda, Yoneda Advanced Casting Co., Ltd., Takaoka, 933-0951 Japan Kyosuke Ueda, Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-6-02, Aza Aoba, Aramaki, Aoba-ku, Sendai, 980-8579 Japan Takayuki Narushima, Department of Materials Processing, Graduate School of Engineering, Tohoku University, 6-6-02, Aza Aoba, Aramaki, Aoba-ku, Sendai, 980-8579 Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Copper precipitation has been studied by thermoelectric power measurements in a high strength interstitial free steel processed under various conditions like batch annealing (BA) (4 hours at 973 K (700 °C)), continuous annealing (CA) (1 minute at 1093 K (820 °C)) and full annealing (FA) (2 hours at 1173 K (900 °C)). The results show that the kinetics of copper precipitation depend on the annealing pre-treatments which influence the amount of copper in solid solution before aging. Extensive copper precipitation associated with a marked increase in hardness was observed in the CA and FA material aged between 773 K and 873 K (500 °C and 600 °C), however, this precipitation was not detected when the steel was subjected to BA before aging. Content Type Journal Article Pages 1-15 DOI 10.1007/s11661-012-1386-z Authors Radhakanta Rana, Institut für Eisenhüttenkunde, RWTH Aachen, Intzestraße 1, Aachen, 52072 Germany Véronique Massardier, Université de Lyon, CNRS, INSA-Lyon, MATEIS UMR5510, 69621 Villeurbanne, France Shiv Brat Singh, Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur, Kharagpur, 721302 India Omkar Nath Mohanty, Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur, Kharagpur, 721302 India Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    We have previously reported that ultrafine-grained (UFG) microstructures can be obtained in a Co-29Cr-6Mo (wt pct) alloy by utilizing dynamic recrystallization (DRX) that occurs during conventional hot deformation (Yamanaka et al .: Metall. Mater. Trans. A , 2009, vol. 40A, pp. 1980−94). The present study investigates the novel DRX mechanism of this alloy in detail. The microstructure evolution during hot deformation under relatively high Zener–Hollomon ( Z ) parameter conditions for which ultrafine grains can develop was systematically investigated by electron backscatter diffraction (EBSD) and transmission electron microscopy. This alloy exhibited a different flow stress behavior and microstructural development from conventional DRX mechanisms. The deformation microstructure contained a large number of stacking faults, which implies that planar dislocation slip is the primary deformation mechanism in the hot deformation of the Co-29Cr-6Mo alloy due to its abnormally low stacking fault energy (SFE) at elevated temperatures. Inhomogeneities in local strain distributions induced by planar slip will enhance grain subdivision by geometrically necessary (GN) dislocation boundaries. Deformation twinning may also contribute to grain refinement. The DRX mechanism operating in the Co-29Cr-6Mo alloy is discussed by considering the relationships between anomalous dislocation structures, flow stress behavior, texture development, and nucleation behavior. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1303-5 Authors Kenta Yamanaka, Institute for Materials Research, Tohoku University, Sendai, 980-8577 Japan Manami Mori, Institute for Materials Research, Tohoku University, Sendai, 980-8577 Japan Akihiko Chiba, Institute for Materials Research, Tohoku University, Sendai, 980-8577 Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Microstructural evolution taking place during equal-channel angular pressing was studied in a commercial Al-6Mg-0.3Sc alloy at 523 K (250 °C) (~0.5 T m ). The structural changes are mainly associated with development of microshear bands (MSBs) that are continuously formed by strain accumulation and microstructural heterogeneities in each pass, which result in fragmentation of coarse original grains. New ultrafine grains (UFGs) with moderate-to-high angle boundary misorientations are concurrently evolved in the interiors of MSBs accompanied by rigid body rotation at medium-to-large strains. Such strain-induced grain refinement process occurs very slowly and incompletely in the present heavily alloyed Al alloy, leading to formation of a mixed microstructure, i.e. , the UFGs in colony and some weakly misoriented fragments of original grains. The microstructure evolved at ε  ≈ 12 is characterized by a bimodal crystallite size distribution with two peaks at d 1  ≈ 0.2 to 0.3  μ m and d 2  ≈ 0.6 to 0.7  μ m, and the fraction of high angle boundaries of about 0.35 ± 0.05. The main factors promoting dynamic formation of UFGs and the effects of thermal processes on it during severe plastic deformation are discussed in detail. Content Type Journal Article Pages 1-14 DOI 10.1007/s11661-012-1438-4 Authors Oleg Sitdikov, Institute for Metals Superplasticity Problems, Russian Academy of Sciences, Khalturina 39, Ufa, 450001 Russia Elena Avtokratova, Institute for Metals Superplasticity Problems, Russian Academy of Sciences, Khalturina 39, Ufa, 450001 Russia Taku Sakai, UEC Tokyo (the University of Electro-Communications), Chofu, Tokyo 182-8585, Japan Kaneaki Tsuzaki, National Institute for Materials Science, Tsukuba, 305-0047 Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The thermal conductivity of some common and experimental high pressure diecasting (HPDC) Al-Si-Cu alloys is evaluated. It is shown that the thermal conductivity of some compositions may be increased by more than 60 pct by utilizing T7 heat treatments. This may have substantial performance and cost benefits for applications where thermal management is a key design parameter. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1443-7 Authors Roger N. Lumley, CSIRO Future Manufacturing Flagship, Private Bag 33, Clayton South MDC, VIC 3169, Australia Natalia Deeva, CSIRO Process Science and Engineering, Clayton, VIC 3169, Australia Robert Larsen, TPRL, Inc., 3080 Kent Ave., West Lafayette, IN 47906, USA Jozef Gembarovic, TA Instruments Corp., 159 Lukens Drive, New Castle, DE 19720, USA Joe Freeman, TPRL, Inc., 3080 Kent Ave., West Lafayette, IN 47906, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The microstructure evolution of 25Cr-35Ni-1Mo radiant tubes was investigated after approximately two years of service in a continuous annealing furnace. The inner and outer tube walls were exposed to N 2 -containing combustion environment and protective atmosphere, respectively. The decarburization feature analysis indicated that carbon content decreased toward the tube surface. However, precipitates at the inner and outer walls were coarser, their content increased and the microhardness value also increased compared to that in the central area. X-ray diffraction illustrated that M 2 (C,N) and M 6 (C,N) were the dominant carbide at the inner and outer walls, and precipitates in the central area were mainly M 23 C 6  and M 6 (C,N) phases. The results were assumed to be associated with the nitridation phenomenon that occurred in the N 2 -containing environment at elevated temperatures. Content Type Journal Article Pages 1-7 DOI 10.1007/s11661-012-1302-6 Authors Zhichao Zhu, School of Material Science and Engineering, Dalian University of Technology, Dalian, 116085 People’s Republic of China Congqian Cheng, School of Material Science and Engineering, Dalian University of Technology, Dalian, 116085 People’s Republic of China Chunhui Liu, School of Material Science and Engineering, Dalian University of Technology, Dalian, 116085 People’s Republic of China Jie Zhao, School of Material Science and Engineering, Dalian University of Technology, Dalian, 116085 People’s Republic of China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Investment casting is a time-consuming, labour intensive process, which produces complex, high value-added components for a variety of specialised industries. Current environmental and economic pressures have resulted in a need for the industry to improve current casting quality, reduce manufacturing costs and explore new markets for the process. Alumino-silicate based refractories are commonly used as both filler and stucco materials for ceramic shell production. A new ceramic material, norite, is now being produced based on ferrous aluminosilicate chemistry, having many potential advantages when used for the production of shell molds for casting aluminum alloy. This paper details the results of a direct comparison made between the properties of a ceramic shell system produced with norite refractories and a typical standard refractory shell system commonly used in casting industry. A range of mechanical and physical properties of the systems was measured, and a full-scale industrial casting trial was also carried out. The unique properties of the norite shell system make it a promising alternative for casting aluminum based alloys in the investment foundry. Content Type Journal Article Pages 1-11 DOI 10.1007/s11661-012-1352-9 Authors Chen Yuan, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT UK Sam Jones, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT UK Stuart Blackburn, School of Metallurgy and Materials, The University of Birmingham, Birmingham, B15 2TT UK Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    In the present study, a ferritic light-weight steel was tempered at 973 K (700 °C) for various tempering times, and tensile properties and deformation mechanisms were investigated and correlated to microstructure. κ-carbides precipitated in the tempered band-shaped martensite and ferrite matrix, and the tempered martensite became more decomposed with increasing tempering time. Tempering times for 3 days or longer led to the formation of austenite as irregular thick-film shapes mostly along boundaries between the tempered martensite and the ferrite matrix. Tensile tests of the 1-day-tempered specimen showed that deformation bands were homogeneously spread throughout the specimen, and that the fine carbides were sufficiently deformed inside these deformation bands resulting in high strength and ductility. The 3-day-tempered specimen showed a small amount of boundary austenite, which readily developed voids or cracks and became sites for fracture. This cracking at boundary austenites became more prominent in the 7- and 15-day-tempered specimens, as the volume fraction of boundary austenites increased with increasing tempering time. These findings suggested that, when the steel was tempered at 973 K (700 °C) for an appropriate time, i.e ., 1 day, to sufficiently precipitate κ-carbides and to prevent the formation of boundary austenites, that the deformation occurred homogeneously, leading to overall higher mechanical properties. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1370-7 Authors Seung Youb Han, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Korea Sang Yong Shin, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Korea Byeong-Joo Lee, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Korea Sunghak Lee, Center for Advanced Aerospace Materials, Pohang University of Science and Technology, Pohang, 790-784 Korea Nack J. Kim, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, 790-784 Korea Jai-Hyun Kwak, Automotive Steels Research Group Technical Research Laboratories, POSCO, Gwangyang, 545-711 Korea Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The replacement of nodular cast iron with 319 type aluminum (Al) alloys in gasoline engine blocks is an example of the shift towards the use of lighter alloys in the automotive industry. However, excessive residual stress along the cylinder bore may lead to bore distortion, significantly reducing engine operating efficiency. In the current study, microstructure, mechanical properties and residual stress were characterized along the cylinder bridge of engine blocks following thermal sand reclamation (TSR), T7 heat treatment, and service testing of the casting. Neutron diffraction was effectively used to quantify the residual stress along both the Al cylinder bridge and the adjacent gray cast iron cylinder liners in the hoop, radial, and axial orientations with respect to the cylinder axis. The results suggest that an increase in cooling rate along the cylinder caused a significant refinement in microstructure at the bottom of the cylinder. In turn, this suggested an increase in alloy strength at the bottom of the cylinder relative to the top. This increased strength at the bottom of the cylinder likely reduced the susceptibility of the cylinder to rapid relief of residual stress at elevated temperature. In contrast, the coarse microstructure at the top of the cylinder likely triggered stress relief at an elevated temperature. Content Type Journal Article Pages 1-13 DOI 10.1007/s11661-012-1340-0 Authors Anthony Lombardi, Centre for Near-Net-Shape Processing of Materials, Ryerson University, Toronto, ON M5B 2K3, Canada Francesco D’Elia, Centre for Near-Net-Shape Processing of Materials, Ryerson University, Toronto, ON M5B 2K3, Canada Comondore Ravindran, Centre for Near-Net-Shape Processing of Materials, Ryerson University, Toronto, ON M5B 2K3, Canada Dimitry Sediako, Canadian Neutron Beam Centre, National Research Council, Chalk River, ON K0J 1J0, Canada B. S. Murty, Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai, 600 036 India Robert MacKay, Nemak of Canada Corporation, Windsor, ON N9C 4G8, Canada Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    It has been well known that the flaking failure in rolling contact fatigue (RCF) originates from nonmetallic inclusions in steels, and their apparent size is one of the important factors affecting RCF life. However, the influence of inclusion shape on the RCF life has not been fully clarified. In this study, attention was paid to the influence of the inclusion shape on the RCF life. This was evaluated by using carburized JIS-SCM420 (SAE4320) steels that contained two different shapes of MnS—stringer type and spheroidized type—as inclusions. Sectional observations were made to investigate the relation between the occurrence of shear crack in the subsurface and the shape of MnS. It was found that the RCF life was well correlated with the length of MnS projected to the load axis, and the initiation of shear crack in subsurface was accelerated as the length of MnS increased. Content Type Journal Article Category Symposium: Fatigue & Corrosion Damage in Metallic Materials: Fundamentals, Modeling, and Prevention (2012) Pages 1-10 DOI 10.1007/s11661-012-1344-9 Authors Yutaka Neishi, Corporate Research & Development Laboratories, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Taizo Makino, Corporate Research & Development Laboratories, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Naoki Matsui, Corporate Research & Development Laboratories, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Hitoshi Matsumoto, Products Development Department, Kokura Steel Works, Bar & Wire Rod Company, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Masashi Higashida, Products Development Department, Kokura Steel Works, Bar & Wire Rod Company, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Hidetaka Ambai, Products Development Department, Kokura Steel Works, Bar & Wire Rod Company, Sumitomo Metal Industries, Ltd., Amagasaki, Hyogo 660-0891, Japan Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The microstructural evolution during friction surfacing of an aluminum alloy 6082-T6 rod on an aluminum alloy 2024-T351 substrate was characterized using the electron backscatter diffraction technique. Crystallographic data were obtained from several regions in the consumable material and in the deposited material. From the results, it can be deduced that the grain structure formation was a complex process governed by the geometrical effect of strain and the superposition of continuous and discontinuous dynamic recrystallizations. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1345-8 Authors U. Suhuddin, Solid State Joining Processes Department, Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, 21502 Geesthacht, Germany S. Mironov, Department of Materials Processing, Graduate School of Engineering, Tohoku University, Sendai, 980-8579 Japan H. Krohn, Solid State Joining Processes Department, Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, 21502 Geesthacht, Germany M. Beyer, Solid State Joining Processes Department, Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, 21502 Geesthacht, Germany J. F. Dos Santos, Solid State Joining Processes Department, Institute of Materials Research, Materials Mechanics, Helmholtz-Zentrum Geesthacht, Centre for Materials and Coastal Research, 21502 Geesthacht, Germany Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Ultra-small-angle X-ray scattering (USAXS) is employed to quantify the average size, interparticle spacing, and volume fraction of the primary B2 precipitates in Fe-based superalloys with varying Al concentration. The results are analyzed with a model incorporating polydispersity and interference effects and verified by transmission electron microscopy (TEM) characterizations. As the Al amount increases from 4 to 10 mass pct, there is an approximately 40 pct decrease in the average interparticle spacing and ~30 pct reduction in the average particle diameter. Content Type Journal Article Category Communication Pages 1-5 DOI 10.1007/s11661-012-1318-y Authors Shenyan Huang, Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200, USA Gautam Ghosh, Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208-3108, USA Xin Li, Indiana University Center for the Exploration of Energy and Matter, Bloomington, IN 47408, USA Jan Ilavsky, X-Ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439, USA Zhenke Teng, Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200, USA Peter K. Liaw, Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996-2200, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    (Ba 0.3 Sr 0.7 )[(Zn 1– x Mg x ) 1/3 Nb 2/3 ]O 3 (BSZMN, x  = 0.4, 0.6, and 0.8) solid-solution ceramics were synthesized by the conventional solid-state synthesis technique. X-ray diffraction (XRD) and vibration spectra (Raman spectroscopy and Fourier transform far-infrared reflection spectroscopy) were employed to evaluate effects of synthesis temperatures on crystal structures and lattice vibration modes of these solid solutions. The XRD results reveal that BSZMN ceramics have a phase transformation, from pseudocubic structure to hexagonal distorted perovskite structure with different Mg 2+ concentration and different synthesis temperatures, i.e. , symmetry decreases with increasing synthesis temperatures. From Raman spectra, synthesis temperatures have an obvious influence on the phonon modes, which are closely related to the 1:2 ordered structure. Variation of the phonon parameters corresponds to the ordering degree; however, the phase transformation and the second phase can influence the phonon characteristics. The results are also proved by far-infrared reflection analyses. Content Type Journal Article Pages 1-12 DOI 10.1007/s11661-012-1349-4 Authors Helei Dong, College of Physics & Electronics, Shandong Normal University, Jinan, 250014 P.R. China Feng Shi, College of Physics & Electronics, Shandong Normal University, Jinan, 250014 P.R. China Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Undoped ZnO and Mn-doped ZnO (MZO) films with 0.25, 0.50, and 0.75 mol pct were synthesized onto glass substrates by sol-gel spin-coating technique, and the effects of Mn on structural, morphologic, and optical properties were investigated. The XRD results indicate that the films have wurtzite structure with polycrystalline nature. However, the dominant peak was (002) diffraction peak for all samples; other diffraction peaks with less intensity such as (100), (101), (102), (110), (103), (112), and (004) were observed for the undoped ZnO. The lattice parameter values of MZO thin films were lower than that of the undoped ZnO. Plane stress values indicated that the films had the tensile stress. A decrease in the grain sizes was observed with the increasing Mn mole percent. The optical transmission values were found to be 82 pct for the undoped ZnO and 80, 78, and 75 pct for the MZO with 0.25, 0.50, and 0.75 mol pct, respectively, at the wavelength of 405 nm. The optical band gap values decreased from 3.287 to 3.270 eV, the surface roughness values increased from 58.13 to 60.67 nm, Urbach energy values increased—a 18.3-meV difference in Urbach energy was observed—and in addition, the steepness parameters decreased with increasing Mn content from 0 to 0.75 mol pct. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1365-4 Authors Eyüp F. Keskenler, Department of Physics, Faculty of Arts and Sciences, Recep Tayyip Erdoğan University, 53100 Rize, Turkey Seydi Doğan, Department of Physics, Faculty of Science, Atatürk University, 25240 Erzurum, Turkey Güven Turgut, Department of Physics, Kazım K. Education Faculty, Atatürk University, 25240 Erzurum, Turkey Bekir Gürbulak, Department of Physics, Faculty of Science, Atatürk University, 25240 Erzurum, Turkey Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Fatigue crack growth experiments in air at 295 K (22 °C) were conducted on 6.35 mm thick plate samples of a commercial Al-Mg alloy machined from the L-T orientation. Thermal exposures for times up to 2000 hours at 343 K, 353 K, 373 K, and 448 K (70 °C, 80 °C, 100 °C, and 175 °C) produced sensitization and delamination in the S-T plane during fatigue testing, dependent on the level of thermal exposure and K max employed. Identical tests conducted in a “dry” environment produced no delamination, indicating that environment may enhance the phenomena. Content Type Journal Article Category Communication Pages 1-5 DOI 10.1007/s11661-012-1361-8 Authors Justin K. Brosi, Department of Materials Science & Engineering, Case Western Reserve University, White Metallurgy Building, Cleveland, OH 44106, USA S. Mohsen Seifi, Department of Materials Science & Engineering, Case Western Reserve University, White Metallurgy Building, Cleveland, OH 44106, USA John J. Lewandowski, Department of Materials Science & Engineering, Case Western Reserve University, White Metallurgy Building, Cleveland, OH 44106, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    A uniform layer of the Cu 5 Zn 8 phase is formed at the Sn-9 wt pct Zn (Sn-9Zn)/Cu interface after reflow at 503 K (230 °C) but fractures very severely during subsequent solid-state aging at 443 K (170 °C). Such a severe fracture of an interfacial intermetallic compound deteriorates the integrity of joint interface and leads to excessive atomic interdiffusion as well as intermetallic compound growth. In the current study, it was observed that by inserting an electroless palladium (Pd) layer at the Sn-9Zn/Cu interface, a Pd 2 Zn 9 phase is formed between Cu 5 Zn 8 and Sn-9Zn solders. This Pd 2 Zn 9 phase exhibits higher microstructural stability at the interface during solid-state aging and effectively retards the fracture of the Cu 5 Zn 8 phase. The integrity of the Sn-9Zn/Cu interface is improved remarkably. Mechanical tests reveal that the shear strength of the Sn-9Zn/Cu joint is enhanced by inserting an electroless Pd layer at the interface. Content Type Journal Article Pages 1-6 DOI 10.1007/s11661-012-1377-0 Authors Po-Hsun Lee, Department of Chemical Engineering, National Chung-Hsing University, Taichung, 402 Taiwan R.O.C. Chi-Pu Lin, Department of Chemical Engineering, National Chung-Hsing University, Taichung, 402 Taiwan R.O.C. Chih-Ming Chen, Department of Chemical Engineering, National Chung-Hsing University, Taichung, 402 Taiwan R.O.C. Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The homogenization practice for EN AW 6005A was investigated. It requires an 8-hour soaking at 853 K (580 °C) to even out the Mg and Si distribution in the aluminum matrix and to fully transform the monoclinic β-Al 5 FeSi plates into relatively small round α c -Al 12 (Fe,Mn) 3 Si particles with a “necklace” type configuration. It is predominantly the equilibrium β-Mg 2 Si phase that precipitates during subsequent cooling at 1000 K h −1  while orthogonal β′-Mg 2 Si platelets are also noted starting at 500 K h −1 . The hardness decreases with decreasing cooling rate from 41.1 ± 1 HV to 35.8 ± 0.8 HV, by 15 pct, over the range investigated. The precipitation capacity retained in homogenized samples cooled to room temperature at less than 250 K h −1  is reduced substantially. The solvus temperatures of these samples are below 773 K (500 °C) ensuring full solutionizing of the Mg 2 Si precipitates below the press exit temperatures typically employed by extruders. An 8-hour soaking at 853 K (580 °C) followed by cooling at 250 K h −1  is identified to be the optimum homogenization treatment as it gives a homogeneous structure with predominantly spherical-shaped α c -Al 12 (Fe,Mn) 3 Si particles and sufficiently low hardness for improved extrudability and a solvus temperature below 773 K (500 °C) to ensure adequate age-hardening capacity. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1379-y Authors Yucel Birol, Materials Institute, Marmara Research Centre, TUBITAK, Kocaeli, Turkey Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    The United Kingdom faces a looming energy gap with around 20 pct of its generating capacity due for closure in the next 10 to 15 years as a result of plant age and new European legislation on environmental protection and safety at work. A number of solutions exist for this problem including the use of new materials so that new plants can operate at higher temperatures, new technologies related to carbon capture and gasification, development of renewable resources, and less obviously the use of accurate models for predicting creep life. This article reviews, with illustrations, some of the more applicable and successful creep prediction methodologies used by academics and industrialists and highlights how these techniques can help alleviate the looming energy gap. The role that these approaches can play in solving the energy gap is highlighted throughout. Content Type Journal Article Pages 1-19 DOI 10.1007/s11661-012-1293-3 Authors Mark Evans, College of Engineering, Swansea University, Swansea, SA2 8PP U.K. Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    An isothermal transformation was observed when a fully austenitized lean-alloyed, low C steel was quenched to a temperature in the M S to M f temperature range and held at the quenching temperature. The dilatometric analysis revealed that the isothermal transformation was distinct from the bainitic transformation. Internal friction (IF) measurements and X-ray diffraction (XRD) analysis showed that the dislocation density in the isothermal transformation product was larger than in lower bainite, and lower than in athermal martensite. Microstructural analysis by transmission electron microscopy (TEM) revealed that the isothermal transformation product had a specific microstructure consisting of large lath-type constituent units with wavy boundaries, with a Nishiyama–Wassermann orientation relationship (NW OR) with respect to the parent austenite. The isothermal transformation below M S proceeds by the thickening of athermally formed laths. Content Type Journal Article Pages 1-17 DOI 10.1007/s11661-012-1338-7 Authors Donghwi Kim, Materials Design Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, 790-784 South Korea Seok-Jae Lee, Materials Design Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, 790-784 South Korea Bruno C. De Cooman, Materials Design Laboratory, Graduate Institute of Ferrous Technology, Pohang University of Science and Technology, Pohang, 790-784 South Korea Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623

Description:    Friction stir welding generates periodic features within the weld. These “onion ring” features are associated with variations in both texture and the orientation of that texture along the length of the weld. Analysis of an AA2195 friction stir weld reveals the presence of periodic oscillations between the dominant B and \text B   components of the ideal shear texture, suggesting a periodic reversal in the predominant shear orientation during welding that is inconsistent with current understandings of the friction stir welding process. Microstructural features present in the weld and machine force variations during welding indicate that these textures may arise from the oscillation of an off-centered tool. Such a tool oscillation can generate a periodic extrusion of material around the tool, giving rise to the observed flow features, machine force variations, and reversals of the local shear texture orientations. A new model of material flow during friction stir welding is proposed to explain the observed features. Content Type Journal Article Pages 1-8 DOI 10.1007/s11661-012-1460-6 Authors Richard Fonda, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375, USA Anthony Reynolds, University of South Carolina, Columbia, SC, USA C. R. Feng, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375, USA Keith Knipling, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375, USA David Rowenhorst, Naval Research Laboratory, 4555 Overlook Ave., SW, Washington, DC 20375, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623