ALBERT

Description: When we appreciate the digital revolution carried over from the twentieth century with mobile communication and the Internet, and when we enjoy our high-tech lifestyle filled with iDevices, hybrid cars, wind turbines, and solar cells in this new century, we should also appreciate that all of these advanced products depend on rare earth metals to function. Although there are only 136,000 tons of annual worldwide demand, (Cho, Rare Earth Metals, Will We Have Enough?) 1 rare earth metals are becoming such hot commodities on international markets, due to not only to their increasing uses, including in most critical military hardware, but also to Chinese growth, which accounts for 95% of global rare earth metal production. Hence, the 2013 technical calendar topic, planned by the TMS/Hydrometallurgy and Electrometallurgy Committee, is particularly relevant, with four articles (including this commentary) contributed to the JOM October Issue discussing rare earth metals’ resourcefulness and recovery.

Description: Rare-earth elements (REEs) are used in lighting and optical applications to enable color and light adjustment, miniaturization, and energy efficiency. Common applications of REEs include phosphors for light-emitting diodes, lasers, and electronic video displays. This article reviews how REEs are widely used in these applications. However, supply constraints, including rising prices, environmental concerns over mining and refining processes, and China’s control over the supply of the vast majority of REEs, are of concern for manufacturers. In view of these supply constraints, this article discusses ways for manufacturers of lighting and optical devices to identify potential substitutes and recycling methods for REEs.

Description: Conventional processing of molybdenum sulfide concentrates involves decades-old technology and often inefficient processing. Molybdenum trioxide (MoO 3 ) is produced from the sulfide concentrate and used by the steel industry to produce steel alloys. An alternative and more attractive molybdenum product, molybdenum dioxide (MoO 2 ), is produced using the Looping Sulfide Oxidation process. By examining the thermodynamics of the molybdenum-sulfur-oxygen system, the conditions necessary to selectively produce MoO 2 over the trioxide have been identified. Under such conditions, oxygen, MoO 3 , or a mixture of the two can be used to convert the sulfide concentrate. Some of the resulting MoO 2 is collected as final product, while some is oxidized to MoO 3 and looped back to the conversion furnace to complete the cycle. A thermodynamic analysis of the reaction schemes and a discussion of the potential for energy capture are presented. The Looping Sulfide Oxidation process presents a paradigm shift in the production and consumption of molybdenum.

Description: Traditional first-principles calculations excel at providing formation energies at absolute zero, but obtaining thermodynamic information at nonzero temperatures requires suitable sampling of all the excited states visited in thermodynamic equilibrium, which would be computationally prohibitive via brute-force quantum mechanical calculations alone. In the context of solid-state alloys, this issue can be addressed via the coarse-graining concept and the cluster expansion formalism. This process generates simple, effective Hamiltonians that accurately reproduce quantum mechanical calculation results and that can be used to efficiently sample configurational, vibrational, and electronic excitations and enable the prediction of thermodynamic properties at nonzero temperatures. Vibrational and electronic degrees of freedom are formally eliminated from the problem by writing the system’s partition function in a nested form in which the inner sums can be readily evaluated to yield an effective Hamiltonian. The remaining outermost sum corresponds to atomic configurations and can be handled via Monte Carlo sampling driven by the resulting effective Hamiltonian, thereby delivering thermodynamic properties at nonzero temperatures. This article describes these techniques and their implementation in the alloy theoretic automated toolkit, an open-source software package. The methods are illustrated by applications to various alloy systems.

Description: Whisker and hillock formation in thin films is well known as a highly local mechanism for stress relaxation, where in many cases, only a few whiskers form out of thousands of grains in a film. In this article, the microstructural characteristics for specific grains to form whiskers in β -Sn films are discussed in light of our recent whisker growth model, establishing a relationship among grain boundary sliding limited Coble creep, surface grain geometry, and film stress for different stress conditions, including for thermal cycling. Through our recent finite-element simulations of stresses induced by room-temperature aging and thermal cycling of textured microstructures, the role of elastic and thermoelastic anisotropy in creating preferred whisker formation sites and the general propensity of a film to form whiskers have been proposed for a range of β -Sn film textures. Taken together, these models suggest a strategy for identifying the effects of local microstructure and β -Sn anisotropy on whisker formation. If these predictions are accurate, then whisker growth risk may be effectively reduced by engineering film microstructures and textures for specific applications and stress conditions.

Description: In the current study, the phase evolution of multicomponent equiatomic CoCrCuFeNi, CoCuFeNi, CoCrCuNi, and CoCrFeNi alloys synthesized by mechanical alloying (MA) followed by annealing was studied. From the phase evolution studies, CoCrFeNi, CoFeMnNi, CoCuFeNi, and CoFeNi were chosen to correlate the densification together with phase evolution during spark plasma sintering (SPS). MA resulted in a major face centered cubic (fcc) phase and a minor body centered cubic (bcc) phase in Cr-containing alloys, and a single fcc phase in all other alloys. After SPS, CoFeMnNi and CoFeNi remained as single fcc phase. However, CoCuFeNi transformed to two fcc phases, and CoCrFeNi had a major fcc phase with minor sigma phase. From densification studies, it was evident that CoCrFeNi showed delayed densification, albeit maximum final densification in comparison to other alloys. This behavior was attributed to distinctly different phase evolution in CoCrFeNi during SPS as compared to other alloys. Detailed phase evolution studies were carried out on CoCrFeNi by annealing the powders at different temperatures followed by conventional x-ray diffraction (XRD) and in situ high-temperature XRD of mechanically alloyed powders. The results obtained from the annealing and in situ high-temperature XRD studies were correlated with the densification and alloying behavior of CoCrFeNi alloy.

Description: High-entropy alloys (HEAs) are newly emerging advanced materials. In contrast to conventional alloys, HEAs contain multiple principal elements, often five or more in equimolar or near-equimolar ratios. The basic principle behind HEAs is that solid-solution phases are relatively stabilized by their significantly high entropy of mixing compared to intermetallic compounds, especially at high temperatures. This makes them feasibly synthesized, processed, analyzed, and manipulated, and as well provides many opportunities for us. There are huge numbers of possible compositions and combinations of properties in the HEA field. Wise alloy design strategies for suitable compositions and processes to fit the requirements for either academic studies or industrial applications thus become especially important. In this article, four core effects were emphasized, several misconceptions on HEAs were clarified, and several routes for future HEA research and development were suggested.

Description: Aluminum alloys with high stacking fault energies have difficulty forming deformation twins at room temperature and at a low strain rate. In this study, several deformation twins were found in Al-10.0Zn-3.0Mg-1.8Cu alloy powders after being cryomilled for a certain period of time. Annealing twins were also found in the same powders after they had been cryomilled first and then placed at an ambient temperature for a longer period of time, up to 2 years. It is suggested that the Venables model on deformation twins is plausible to explain the twin propensity formed in these powders. The study of the formation mechanism of both deformation and annealing twins concludes that twinning deformation can reduce the grain boundary energy of the alloy powders when the powders are cryomilled first and then placed at the ambient temperature for a longer period of time, up to 2 years.

Description: Consideration of the environmental and societal impacts of engineering products and processes is becoming increasingly important, so sustainability-related issues need to be addressed in educating engineers. Awareness of sustainability issues is particularly important for materials and metallurgical scientists and engineers because they are involved in both developing processes and selecting materials with low-energy use and low environmental impact. In this article, activities at TMS to identify sustainability-related educational needs and opportunities to address these needs will be discussed.

Description: In recent years, the deterioration in the available coke quality for anode production has led to increased levels of metal impurities such as nickel and vanadium in primary aluminum. There is growing concern from the industry with regard to the impact of increased Ni and V levels on the downstream properties of Al alloy products. This article presents a detailed investigation of the influences of Ni and V impurities on microstructure of three common Al alloys, i.e., AA6063, AA3102, and A356, in both as-cast and heat-treated conditions. The characterization techniques employed include scanning electron microscopy, electron backscattered diffraction, energy-dispersive x-ray spectroscopy, wavelength-dispersive spectroscopy, and transmission electron microscopy. It is shown that the phase constituents of AA6063 are not altered by Ni additions up to 0.05% or V additions up to 0.04%. Whereas there is no change in phase constituents with increasing Ni up to 0.015% for AA3102, the addition of 0.05% Ni seems to have significant influence on the microstructure. For A356, Ni additions up to 0.02% do not seem to have significant influence on the microstructure, but a new phase with significantly high Ni content is formed when the Ni impurity level is increased to 0.05%. The deep insight obtained in this work should be helpful to understand the influences of Ni and V impurities on properties of Al alloys.

Description: To establish the efficiency of electromagnetically assisted tube hydroforming, a typical experimental test for hydroforming, i.e., hydrobulging, was carried out on a 5A02 tube blank by using a combined quasi-static axial feeding and pulsed electromagnetic hydrobulging method. Data on the formability of an aluminum alloy 5A02 tube employing this combined loading method is compared with data for traditional quasi-static tests. The results show that the formability of aluminum alloy undergoing a quasi-static–dynamic process is dramatically increased beyond that exhibited in quasi-static or fully dynamic tests. The ultimate expansion ratio of an aluminum alloy tube undergoing a pulsed electromagnetic hydrobulging process is greatly increased beyond that exhibited in quasi-static hydrobulging tests. Both the expansion ratio and the effective strain exhibited in electromagnetically assisted tube hydroforming tests are about four and two times of that in quasi-static and fully dynamic hydrobulging tests, respectively. The forming limits of aluminum samples with both low and high prestrain levels are almost similar in the electromagnetically assisted tube hydroforming process, which makes it possible to stretch the aluminum alloy to a higher quasi-static prestrain level without weakening its total quasi-static–dynamic formability.

Description: The (ABOw + WO 3 p)/Al hybrid composite was fabricated by squeeze casting and subsequently hot extruded at temperatures that varied from 440°C to 560°C. The microstructures of extruded composites were examined by scanning electron microscopy and transmission electron microscopy techniques. The results show that ABOw aligns along the extrusion direction after the hot extrusion process. The aspect ratio of ABOw in extruded composites is lower than that of as-cast composite. The aspect ratio of ABOw in extruded composites increases with the increase of extrusion temperature. The larger WO 3 p particles are broken into smaller particles during the extrusion process. The transmission electron microscopy (TEM) images show that hot deformation leads to high dislocation density at a lower deformation temperature and leads to grain recovery and recrystallization at a higher deformation temperature. The strength of extruded composites increases first and then decreases with the increase of extrusion temperature, and it reaches maximum value at 500°C. The elongation of extruded composites increases with the increase of extrusion temperature.

Description: Aluminum alloy extrusions with variations in profiles and Fe-rich particles were produced using different extrusion dies and iron contents. A microstructural examination of the extrusion surface shows that the extrusion profile and iron content have a great effect on the size and number of Fe-rich particles, grain size, texture, and fraction of high-angle grain boundaries due to varying localized plastic deformation and temperature in the extrudate. After etching and anodizing, surface imperfections such as grain boundary grooves that influence the final surface appearance are formed on the extrusion surfaces. The severity of grain boundary grooves is found to be directly linked to the number of Fe-rich particles. Hence, the extrusion profile has a dramatic influence on surface imperfections and the appearance of the final anodized extrusions through its effect on the surface microstructure.

Description: Preparation of Ti powders from TiO 2 by calcium vapor reduction was investigated by x-ray diffraction (XRD), scanning electron microscope (SEM), element analysis instrument, inert gas fusion–infrared absorption spectroscopy, and ethylene diamine tetraacetic acid (EDTA) complex formation titration. The experimental results indicate that the reduction reaction occurs very rapidly when the mass ratio of CaCl 2 to TiO 2 is 1:2 from 0 min to 30 min, and the titanium suboxides were further reduced from 30 min to 480 min at 1000°C. The content of CaCl 2 influences the reduction products and the reduction rate obviously, and the suitable mass ratio of CaCl 2 to TiO 2 is 1:2 under these experimental conditions. Ti powders with oxygen content of 1000 ppm, nitrogen content of 120 ppm, and chlorine content of 80 ppm were obtained at 1000°C for 360 min.

Description: An investigation was undertaken using gas tungsten arc (GTA) welding on consolidated powder metallurgy (PM) titanium (Ti) plate to identify the causal factors behind observed porosity in fusion welding. Tramp element compounds of sodium and magnesium, residual from the metallothermic reduction of titanium chloride used to produce the titanium, were remnant in the starting powder and were identified as gas-forming species. PM-titanium made from revert scrap, where sodium and magnesium were absent, showed fusion weld porosity, although to a lesser degree. We show that porosity was attributable to hydrogen from adsorbed water on the surface of the powders prior to consolidation. The removal and minimization of both adsorbed water on the surface of titanium powder and the residues from the reduction process prior to consolidation of titanium powders are critical for achieving equivalent fusion welding success similar to that seen in wrought titanium produced via the Kroll process.

Description: As a brazing foil, 4004 Al alloy has good welding performance. However, the high Si content decreases the plasticity of the alloy. To improve the plasticity of 4004 Al alloy and subsequently improve the productivity of 4004 Al foil or 434 composite foil, 4004 Al alloy was modified by Al-10%Sr master alloy. Modification effects of an additional amount of Sr, modification temperature, and holding time on 4004 aluminum alloy were studied by orthogonal design. The results showed that the greatest impact parameter of 4004 aluminum alloy modification was the additional amount of Sr, followed by holding time and modification temperature. The optimum modification parameters obtained by orthogonal design were as follows: Sr addition of 0.04%, holding time of 60 min, and modification temperature of 760°C. The effect of Sr addition on modification was analyzed in detail based on orthogonal results. With increasing of Sr addition, elongation of 4004 alloy increased at first, and decreased after reaching the maximum value.

Description: The nanoimpact indentation technique is an emerging characterization technique that permits measurement of dynamic properties on a small scale. This article reports results on the characterization of nanostructured and ultrafine-grained Al-Si claddings using this technique. First, it was found that with this technique, the dynamic hardness of the material also becomes independent of the load, similar to nanoidentation, which yields to the concept of the existence of a dynamic true hardness. Second, the plasticity results have been compared to a strain-gradient plasticity model and have shown to deviate from the Nix-Gao model. Finally, a comparison between H / E and DH/ E ratios has shown that the DH/ E ratio correlates better with dry sliding wear results obtained for this material.

Description: Establishing electrical interconnects in implantable electronic medical devices frequently requires joining of dissimilar materials. A weld between a tantalum wire and titanium sheet metal on a contact module is presented as an example for dissimilar joining. Latent, brittle cracking was observed in the proximity of the weld upon pull testing. The weld cracking occurs by the mechanism known as hydrogen stress cracking (HSC) and is due to titanium hydride formation. Diffusion facilitated hydrogen transport into the weld area. Diffusing hydrogen accumulates preferably in regions of high stress, causing latent titanium hydride formation and embrittlement of the weld. A broad array of analytical tools such as scanning electron microscopy (SEM), transmission electron microscopy, electron backscattered diffraction, dynamic secondary ion mass spectroscopy, and nanoindentation were utilized to identify the root cause for HSC.

Description: We document evidence of a unique phase transformation process occurring within the primary alpha regions of a bimodal microstructure during solid-state welding of Ti-6Al-4V. The transformation occurs when material is rapidly and locally heated above the β transus, but the time at temperature is insufficient for complete homogenization of the initially segregated alloying elements in the bimodal microstructure of the base metal. After cooling, the regions of prior primary alpha phase contain chemical, structural, and crystallographic changes. The constituent morphology, crystallography, and chemistry provided insight into the transformation mechanism.

Description: To discover the deformation behavior and corresponding mechanism of the typical material under fluid pressure, we proposed a test method for the uniaxial tensile deformation performance of the sheet under fluid pressure and developed a testing device as well as a special fixture. The aluminum and aluminum alloy were tested based on this method, respectively. The results indicate that under the uniaxial tension, the plastic zone expands significantly and the uniform elongation decreases gradually with the increase of fluid pressure. The uniaxial tensile deformation performances of the sheets are improved differently corresponding to the various fluid pressures, and the increment of the elongation after fracture is higher for aluminum than aluminum alloy. The dimples on the fracture surface of the aluminum and aluminum alloy sheets are directionally distributed under fluid pressure. Aluminum sheets have no significant shear lip and the dimples become relatively evenly rounded. It is shown from our experiment that the deformation performance of the sheet can be significantly improved by applying fluid pressure, which provides a new way to improve the deformation ability of the sheets with low plasticity and expand their applications.

Description: We performed an investigation of the initial stage of oxidation onto a relevant Cr 2 AlC (0001) surface by ab initio calculations. For the most energetically stable Al-terminated Cr 2 AlC (0001) surface, a detailed model describing the oxygen-surface interaction is developed by exploring the adsorption energetics. Based on the evaluation of the energetics and the structural properties of the atomistic models generated, the results point to an initial stage of the Cr 2 AlC (0001) surface oxidation with some similarities with those observed in the Al (111) layer. Our findings on the bonding mechanism of single O adsorption atoms of the surface may lead to further alloying strategies to enhance oxidation resistance in a wide range of refractory-metal-based MAX phases.

Description: The reaction mechanisms for the carbothermic reduction of complex mineral sulfide concentrates in the presence of lime were studied between 1073 K and 1323 K. The reaction mechanisms were studied by stopping the reduction experiments at different times and analyzing the reaction products by x-ray diffraction and scanning electron microscopy techniques. Magnetite (Fe 3 O 4 ) and digenite (Cu 1.8 S) were the initial phases formed during reduction of CuFeS 2 and Cu 5 FeS 4 mineral particles, such that metallization of iron occurred before copper above 1173 K and at an equal stoichiometric ratio of CaO and C. The metallization of iron was found to take place via reduction of intermediate oxide phase (Fe 3 O 4 /FeO), whereas metallization of copper occurred via diffusion of S 2− ions away from the mineral particles or via formation of Cu-O-S liquid phase. Metallic iron and cobalt were embedded in the copper matrix due to a preferential reduction of iron and cobalt from the Cu-Fe-S and Cu-Co-S type of mineral particles. The effects of CaO/C ratio were analyzed and the rate of reactions was increasing with an increase in the CaO/C ratio. The formation of liquid phase has been discussed. The experimental results were found to be in good agreement with the thermodynamic predictions.

Description: The microstructures of directionally solidified Ni-31Al-32Cr-6Mo (at.%)- x Dy ( x  = 0, 0.1 wt.%) hypereutectic alloys were studied at different withdrawal rates. The results show that the microstructure changes from the planar eutectic to the cellular eutectic and the volume fraction of the primary Cr(Mo) dendrites decreases for the Dy-free alloy with the withdrawal rate varying from 6  μ m/s to 30  μ m/s. The addition of 0.1 wt.% Dy promotes the planar-to-cellular transition. Moreover, the white Dy-containing phase does not form in the alloy for the planar interface growth (6  μ m/s), but it can occur in the boundary of eutectic cells for the cellular interface growth (30  μ m/s). A sketchy model of the planar and cellular growth is supposed to interpret it.

Description: We report our research activities on density functional theory-based alloy thermodynamics, including method/software developments, the integration of first-principles calculations, CALPHAD modeling, and the automation of phase diagram calculations. Examples to be discussed include phonon dispersions of rhombohedral BiFeO 3 , the solution to the long-outstanding problem of imaginary phonon frequencies for cubic perovskites using EuTiO 3 as an example, the calculation of excess specific heat for the magnetic phase transition in EuTiO 3 , and the automated calculation of a phase diagram for the Al-Mg system.

Description: This article presents the salient features of a new process for the recovery of metal values from secondary sources and waste materials such as slag and flue dusts. It is also feasible in extracting metals such as nickel and cobalt from ores that normally are difficult to enrich and process metallurgically. The salt extraction process is based on extraction of the metals from the raw materials by a molten salt bath consisting of NaCl, LiCl, and KCl corresponding to the eutectic composition with AlCl 3 as the chlorinating agent. The process is operated in the temperature range 973 K (700°C) to 1173 K (900°C). The process was shown to be successful in extracting Cr and Fe from electric arc furnace (EAF) slag. Electrolytic copper could be produced from copper concentrate based on chalcopyrite in a single step. Conducting the process in oxygen-free atmosphere, sulfur could be captured in the elemental form. The method proved to be successful in extracting lead from spent cathode ray tubes. In order to prevent the loss of AlCl 3 in the vapor form and also chlorine gas emission at the cathode during the electrolysis, liquid aluminum was used. The process was shown to be successful in extracting Nd and Dy from magnetic scrap. The method is a highly promising process route for the recovery of strategic metals. It also has the added advantage of being environmentally friendly.

Description: The Australian minerals processing and extractive metallurgy industries are responsible for about 20% of Australia’s total greenhouse gas (GHG) emissions. This article reviews the potential applications of concentrated solar thermal (CST) energy in the Australian minerals processing industry to reduce this impact. Integrating CST energy into these industries would reduce their reliance upon conventional fossil fuels and reduce GHG emissions. As CST technologies become more widely deployed and cheaper, and as fuel prices rise, CST energy will progressively become more competitive with conventional energy sources. Some of the applications identified in this article are expected to become commercially competitive provided the costs for pollution abatement and GHG mitigation are internalized. The areas of potential for CST integration identified in this study can be classed as either medium/low-temperature or high-temperature applications. The most promising medium/low-grade applications are electricity generation and low grade heating of liquids. Electricity generation with CST energy—also known as concentrated solar power—has the greatest potential to reduce GHG emissions out of all the potential applications identified because of the 24/7 dispatchability when integrated with thermal storage. High-temperature applications identified include the thermal decomposition of alumina and the calcination of limestone to lime in solar kilns, as well as the production of syngas from natural gas and carbonaceous materials for various metallurgical processes including nickel and direct reduced iron production. Hybridization and integration with thermal storage could enable CST to sustain these energy-intensive metallurgical processes continuously. High-temperature applications are the focus of this paper.

Description: In this article, the mathematical model of vanadium carbide growth was established on the basis of principles of physical chemistry. Based on the results of the experimental work and literature data, the assumption that the speed of the process is proportional to the thermodynamic activity of carbon in the austenite has been proven. An analysis of the relationship between the thickness of the vanadium carbide layer and the salt bath temperature, immersion time, and chemical composition of the substrate was conducted. A comparison of the model-calculated values and the results obtained by the experiment indicates that the model has been properly founded.

Description: High-entropy alloys (HEAs) are a class of alloys that are being considered for a number of applications. In the present study, the microstructures and 1050°C oxidation behaviors of two HEAs, Al 10 Cr 22.5 Co 22.5 Ni 22.5 Fe 22.5 (at.%) and Al 20 Cr 25 Co 25 Ni 25 Si 5 have been investigated along with Al 15 Cr 10 Co 35 Ni 35 Si 5 , which is a high-temperature shape-memory alloy. Oxide formation occurred via selective oxidation in a manner that was consistent with the oxide formation model devised by Giggins and Pettit for model Ni-Cr-Al alloys. The lower Al content alloy formed an external Cr 2 O 3 scale and an internal subscale consisting of Al 2 O 3 and AlN precipitates. The higher Al content alloys exhibited smaller mass gains and formed external Al 2 O 3 scales without any internal oxidation of the alloys.

Description: Integrated computational materials engineering approaches to alloy development leverage the hierarchical, interconnected nature of materials systems to rapidly optimize material performance. Particular emphasis is placed on the use of predictive models and simulation tools to elucidate fundamental relationships within the processing-structure-processing materials paradigm. For the current work, computational simulation results were used in combination with mechanistic, science-based models to assist alloy design. Two case studies are presented as illustrative examples that focus on high-temperature magnesium (Mg) alloy development. Solid solution strengthening potency and solute-based effects on creep rate were discussed in the first case study to guide strategies for solute selection in alloy development. This analysis was completed through the identification of composition-sensitive microstructural parameters that were subsequently evaluated in a predictive fashion. The second case study used computational thermo-kinetic simulations to evaluate Mg alloy precipitate systems for their ability to nucleate a high number density of coarsening-resistant particles. This nucleation and growth analysis was then applied to a Mg-Sn-Al alloy to highlight the utility of the current methodology in predicting multicomponent alloy precipitation behavior. This paper ultimately seeks to provide insight into an integrative approach that captures the important underlying material physics through relationships parameterized by descriptive thermodynamic and kinetic factors, where these factors can be readily calculated with a commercially available suite of computational tools in concert with accessible data in the literature.

Description: After the post heat-treatment (PHT) process of powder metallurgy carbon nanotubes (CNT)/Al composites, micro-cracks were observed in the composites, leading to greatly degraded mechanical properties. To understand and suppress the crack formation, an in situ observation of CNT/Al composites was performed at elevated temperatures. PHT was also applied to various bulk pure Al and CNT/Al composites fabricated under different processes. It was observed that the composites consolidated by hot-extrusion might form micro-cracks, but those consolidated by spark plasma sintering (SPS) showed no crack after PHT. A high-temperature SPS process before hot-extrusion was effective to prevent crack formation. The release of residual stress in severe plastic deformed (SPD) materials was responsible for the cracking phenomena during the PHT process. Furthermore, a good particle bonding was essential and effective to suppress cracks for SPD materials in the PHT process.

Description: Physical and statistical models are combined to describe and design magnesium and high entropy alloys. A principal component analysis is applied to merge material datasets, and it is shown that limits in properties can be envisaged. Extrapolation techniques can be employed to devise properties of non-existing alloys, such as specific heat capacity, melting point and Young’s modulus. These in turn can be input to physical models to predict, for example, yield strength and modulus of toughness. The tools described herein can readily be used for materials discovery, and are being implemented in the Accelerated Metallurgy project.

Description: In this article, we study the physical and mechanical properties of lutetium, which will be compared with the elements of the third-row transition metals (Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Au, Tl, Pb, and Bi). Data mining is an ideal approach for analyzing the information and exploring the hidden knowledge among the data. The purpose of the data mining scheme is to identify and classify the effects of the relationships existing between properties. The results of the investigation are presented by means of multivariate modeling methods, such as the principal component analysis and the partial least squares regression to discover the implicit, yet meaningful, relationship between the elements of the data set, and to locate correlations between the properties of the materials. In this study, we present a data mining approach to discover such unusual correlations between properties of the elements. When comparing the properties of the transition metals with those of lutetium, our results show that lutetium shares many properties and similarities with the transition metals of the sixth row in the periodic table and can be well described as a transition metal.

Description: Graphene is a two-dimensional nanomaterial that has unique electrical, mechanical, thermal, and optical properties. For realizing the practical applications of graphene, one of the major challenges lies in cost-effective production of graphene-based nanomaterials at a large scale. Significant research efforts have been demonstrated in regard to scalable manufacturing of graphene and show strong potential for their commercialization and industrialization. Here, we review the state-of-the-art techniques developed for the scalable production of graphene. This review mainly discusses the top-down techniques including exfoliation of bulk graphite and chemical reduction of graphene oxide. Critical comparison for graphene quality, structure, and yields for different techniques is discussed and specific examples are described in detail.

Description: Graphene is critical for applications in electronics, optical devices, thermal management, energy, and biosystems, while at the same time cost-effective and large-scale production of graphene is a challenge. In this regard, vapor phase graphene synthesis is a bottom-up approach, which could be compatible with device industry fabrication methods. Here, we review the state-of-the-art techniques developed for the scalable production of graphene in bottom-up approaches. These mainly include the epitaxial growth and chemical vapor deposition methods. Product quality, structure, and yields for different graphene growth techniques are discussed and specific examples are described. The article also emphasizes promising methods for scalable graphene production but still needing a deeper research understanding.

Description:    Over the past 10 years, the development of high-power pulsed magnetron sputtering (HPPMS) has shown considerable potential in improving the quality of sputtered films by generating a high degree of ionization of the sputtered species to achieve high plasma density by using pulsed, high peak target power for a short period of time. However, the early HPPMS technique showed a significantly decreased deposition rate as compared to traditional magnetron sputtering. Recently, an alternative HPPMS deposition technique known as modulated pulsed power (MPP) magnetron sputtering has been developed. This new sputtering technique is capable of producing a high ionization fraction of sputter target species and while at the same time achieving a high deposition rate. This paper is aimed at giving a review of recent advances in the MPP technique in terms of the plasma properties, the improvements in the structure and properties of the thin films, and the important advances in the high rate deposition of high quality thick coatings on the order of 20–100 μm in thickness. Content Type Journal Article Pages 48-58 DOI 10.1007/s11837-011-0092-4 Authors Jianliang Lin, Advanced Coatings and Surface Engineering Laboratory (ACSEL), Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, USA William D. Sproul, Advanced Coatings and Surface Engineering Laboratory (ACSEL), Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, USA John J. Moore, Advanced Coatings and Surface Engineering Laboratory (ACSEL), Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, USA Zhili Wu, Advanced Coatings and Surface Engineering Laboratory (ACSEL), Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, USA Sabrina Lee, U.S. Army Benet Laboratories, Watervliet Arsenal, NY 12189, USA Roman Chistyakov, Zond, Inc., Mansfield, MA, USA Bassam Abraham, Zpulser, LLC, Mansfield, Massachusetts 02048, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: Inspiration from Nature—Biomimetic Materials Workshop at the San Diego Zoo Content Type Journal Article Pages 19-20 DOI 10.1007/s11837-011-0085-3 Authors Po-Yu Chen, Departments of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093-0411, USA John A. Nychka, Department of Chemical and Materials Engineering, University of Alberta, Edmonton, AB, Canada T6G 2V4 Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: A project for the ages: Art, history, and materials science converge to preserve the 1297 Magna Carta Content Type Journal Article Pages 13-16 DOI 10.1007/s11837-011-0084-4 Authors Lynne Robinson Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Magnesium (Mg) and its alloys provide numerous benefits as a resorptive biomaterial and present the very real possibility of replacing current metallic implant materials in a variety of roles. The development of suitable biodegradable implant alloys is a multidisciplinary challenge, since alloy design must be confined to a range of alloying additions that are biologically nontoxic, whilst still providing the requisite mechanical properties. This leaves a small number of compatible elements that can provide benefits when alloyed with Mg, including calcium (Ca) and zinc (Zn). To date, although a range of different Mg alloys have been investigated both in vitro and in vivo, little work has been performed to characterize the relationship between the composition of Mg alloys, their corrosion and resulting mechanical properties over time. Consequently it is crucial to understand how these properties may be related if alloys are to be successfully screened for implantation in the body. Content Type Journal Article Pages 28-34 DOI 10.1007/s11837-011-0089-z Authors Nicholas T. Kirkland, Department of Materials Engineering, Monash University, Clayton, 3800 Victoria, Australia Mark P. Staiger, BioMATE Group, Mechanical Engineering Department, University of Canterbury, Engineering Road, Ilam, Christchurch, 8041 New Zealand David Nisbet, Research School of Engineering, The Australian National University, Acton, 0200 Australian Capital Territory, Australia Chris H.J. Davies, Department of Materials Engineering, Monash University, Clayton, 3800 Victoria, Australia Nick Birbilis, Department of Materials Engineering, Monash University, Clayton, 3800 Victoria, Australia Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Friction, wear, and lubrication have direct influence on performance, reliability, and service life of devices that contain moving components. These are universal in applications of energy conversion, power generation, energy harvesting in the broader fields such as agriculture, transportation, drug delivery, and bioengineering. The useful life of these systems and their energy efficiency can be improved by improving the surface properties (performances) of sliding systems. Further, the applications of sliding systems are limited in extreme environments such as high temperature and space application etc. due to their limited surface properties. Therefore, development of a new class of materials with superior surface properties will improve the energy efficiency, sustainability, and applicability. This paper focuses on development of self-lubricating materials with superior surface properties for reduced friction and wear applications. Content Type Journal Article Pages 77-83 DOI 10.1007/s11837-011-0096-0 Authors R. Paluri, Department of Mechanical Engineering, Texas A&M University, College Station, TX, USA S. Ingole, Marine Engineering Technology and Marine Biology Departments, Texas A&M University, Galveston, Texas, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Adsorption of biomolecules, whether it is a consequence of a material being put into service in a biological medium such as a biomedical implant device or a heat exchanger tube, are governed by fundamental interactions and surface conditions that are well characterized (and in some cases not so well). This work reviews those fundamental interactions and also describes a study of the adsorption of a naturally occurring biological polymer onto a stainless steel alloy. Content Type Journal Article Pages 22-27 DOI 10.1007/s11837-011-0088-0 Authors Douglas C. Hansen, Chemical and Materials Engineering Department, University of Dayton Research Institute, 300 College Park, Dayton, OH 45469, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: Biomaterials II: Corrosion issues in biological environments Content Type Journal Article Pages 21-21 DOI 10.1007/s11837-011-0087-1 Authors Vilupanur A. Ravi, Department of Chemical and Materials Engineering at California State Polytechnic University, Pomona, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: Surface engineering for energy sustainability and bio-applications Content Type Journal Article Pages 69-69 DOI 10.1007/s11837-011-0094-2 Authors Sandip P. Harimkar, Oklahoma State University, Stillwater, USA Arvind Agarwal, Florida International University, Miami, USA Sudipta Seal, University of Central Florida, Orlando, USA Narendra Dahotre, University of North Texas, Denton, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Our goal was to evaluate microvascular endothelial cell growth on microstamped patterns of extracellular matrix proteins (ECM). A combination of photo- and soft-lithography was used to make features ∼100 μm deep and 150μm wide. Polydimethylsiloxane imprints of features produced positive molds used to stamp collagen I, IV, laminin and fibronectin onto cleaned hydrophilic or hydrophobic glass coverslips. Human dermal microvascular endothelial cells were seeded at an initial density of 800 cells cm-2, and cultured for three days. Explanted murine aortas, serving as an initial source for autologous endothelial cells, were perfused at 240 μL min −1 for 1 day. Cell morphology was also quantified on both the non-patterned glass and within the microstamped patterns. Viability was high (〉90%) on all microstamped proteins, regardless of glass hydrophobicity. Viability was reduced on bare hydrophobic glass. Cell density was 4 or 8 fold higher on microstamped ECM proteins compared with hydrophilic or hydrophobic glass, respectively. Confluence was approached more rapidly on microstamped proteins. Thus, rapid concentrated growth of endothelial cells was markedly enhanced within microstamped ECM patterns on hydrophilic and hydrophobic glass. Content Type Journal Article Pages 84-93 DOI 10.1007/s11837-011-0097-z Authors David A. Rubenstein, School of Mechanical and Aerospace Engineering, Oklahoma State University, Stillwater, OK 74078-5016, USA Mary D. Frame, Department of Biomedical Engineering, Stony Brook University, Stony Brook, NY, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: TMS finances: Looking back at a year of progress Content Type Journal Article Pages 12-12 DOI 10.1007/s11837-011-0083-5 Authors Stanley M. Howard Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: Get involved: Subhadarshi Nayak, TMS Professional Registration Committee Content Type Journal Article Pages 104-104 DOI 10.1007/s11837-011-0082-6 Authors Kelly Zappas Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    The influence of temperature and pressure of nitriding on the corrosion resistance of Ti-6Al-4V titanium alloy in 0.9% NaCl was studied. It is shown that forming of nitride film improves the anticorrosion characteristics of the alloy regardless of the temperature of the corrosion environment. At the temperature of 36°C the pressure and temperature of nitriding positively influence the anticorrosion characteristics of the alloy. At 40°C the pressure positively influences the protection of the alloy surface, and the influence of the temperature factor is negative. Content Type Journal Article Pages 35-40 DOI 10.1007/s11837-011-0090-6 Authors I. M. Pohrelyuk, Physical-Mechanical Institute of National Academy of Sciences of Ukraine 5, Naukova St., Lviv, 79601 Ukraine O. V. Tkachuk, Physical-Mechanical Institute of National Academy of Sciences of Ukraine 5, Naukova St., Lviv, 79601 Ukraine R. V. Proskurnyak, Physical-Mechanical Institute of National Academy of Sciences of Ukraine 5, Naukova St., Lviv, 79601 Ukraine Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description: TMS Partners in Progress: The case for recycling of rare earth metals—A CR 3 communication Content Type Journal Article Pages 8-9 DOI 10.1007/s11837-011-0098-y Authors T. Anand, Colorado School of Mines, Golden, USA B. Mishra, Colorado School of Mines, Golden, USA D. Apelian, Worcester Polytechnic Institute, Worcester, USA B. Blanpain, KU Leuven, Leuven, Belgium Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Microneedles are small-scale needle-like projections that may be used for transdermal delivery of pharmacologic agents, including protein-containing and nucleic acid-containing agents. Commercial translation of polymeric microneedles would benefit from the use of facile and cost effective fabrication methods. In this study, visible light dynamic mask microstereolithography, a rapid prototyping technique that utilizes digital light projection for selective polymerization of a liquid resin, was used for fabrication of solid microneedle array structures out of an acrylate-based polymer. Pulsed laser deposition was used to deposit silver and zinc oxide coatings on the surfaces of the visible light dynamic mask microstereolithography-fabricated microneedle array structures. Agar diffusion studies were used to demonstrate the antimicrobial activity of the coated microneedle array structures. This study indicates that light-based technologies, including visible light dynamic mask microstereolithography and pulsed laser deposition, may be used to fabricate microneedles with antimicrobial properties for treatment of local skin infections. Content Type Journal Article Pages 59-68 DOI 10.1007/s11837-011-0093-3 Authors Shaun D. Gittard, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Philip R. Miller, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Chunming Jin, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Timothy N. Martin, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Ryan D. Boehm, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Bret J. Chisholm, Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102, USA Shane J. Stafslien, Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102, USA Justin W. Daniels, Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102, USA Nicholas Cilz, Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102, USA Nancy A. Monteiro-Riviere, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Adnan Nasir, Department of Dermatology, University of North Carolina, Chapel Hill, NC, USA Roger J. Narayan, Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Chapel Hill, NC 27599, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Musculoskeletal and craniofacial implants, and their interactions with the human body, are a very important area of medicine today. Aging populations and rapidly escalating health care costs make the study of implant-body interactions increasingly urgent. One of the major impediments to long-term durability of implant materials is the issue of aseptic loosening, i.e., inflammatory response against the prosthetic metal and metal debris produced by its corrosion. In this research summary, we discuss the corrosion behavior of a new class of boron-containing titanium alloys in physiologically relevant media. In addition, the suitability of these alloys from a mechanical perspective will also be discussed along with implications for alloy design. Content Type Journal Article Pages 42-47 DOI 10.1007/s11837-011-0091-5 Authors Vilupanur A. Ravi, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Shaun Rogers, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Mehnaz Malek, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Daniel Surmenian, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Isaac Priddy, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Bradley Harrison, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Andrew Schissler, Department of Chemical & Materials Engineering, California State Polytechnic University, Pomona, W. Temple Avenue, Pomona, CA 91768, USA Suresh C. Divi, Titanium Metals Corporation (TIMET), 181 N Water St., Henderson, NV 89015, USA Sesh Tamirisakandala, FMW Composite Systems Inc., 1200 W. Benedum Industrial Drive, Bridgeport, WV 26330, USA Daniel Miracle, Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson Air Force Base, Wright-Patterson, OH 45433, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    A wide variety of carbon nanostructures, from zero-dimensional fullerene through one-dimensional carbon nanotube to two-dimensional graphene, have attracted attention of scientific community worldwide for their exciting properties. Carbon-based nanomaterials have found applications in a vast field—electronics, sensors, biotechnology, energy, structural, etc. We have concentrated our effort in developing new engineering nanomaterials (graphene, carbon nanotubes) and their device applications in the field of energy generation and storage, nanoelectronics, and bio-electronic sensors. This article aims to capture those recent research efforts in synthesis and applications of carbonbased nanomaterials. Content Type Journal Article Pages 70-76 DOI 10.1007/s11837-011-0095-1 Authors Indranil Lahiri, Nanomaterials and Device Lab, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33714, USA Santanu Das, Nanomaterials and Device Lab, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33714, USA Chiwon Kang, Nanomaterials and Device Lab, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33714, USA Wonbong Choi, Nanomaterials and Device Lab, Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33714, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    Load-bearing metal implants often fail prematurely due to inadequate biocompatibility, mechanical/tribological properties, and poor osseointegration. It is well known that biomaterials’ surface plays a vital role in the response to these metal implants in the biological environment. The biological effectiveness of artificial implants is determined mainly by their surface characteristics such as surface morphology, microstructure, composition, mechanical properties, wettabilility, and surface free energy. Hence, there is significant interest toward surface modification and effective design of load-bearing metal implants so as to improve their surface properties and thereby elicit a specific, desired, and timely response from the surrounding cells and tissues. In this article, we provide an insight into laser surface modification of Ti/Ti6Al4V alloy with or without functional gradation in composition and their microstructural, in vitro wear and biological properties for various loadbearing orthopedic applications. Content Type Journal Article Pages 94-99 DOI 10.1007/s11837-011-0099-x Authors Amit Bandyopadhyay, W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA Vamsi Krishna Balla, W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA Mangal Roy, W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA Susmita Bose, W.M. Keck Biomedical Materials Research Laboratory, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164-2920, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 6

Description:    This work presents the results of investigation process of copper concentrate roasting in fluidized bed reactor with the aim of studying the transformations of copper concentrate minerals as well as to check the accordance with theoretical predictions. The roasted samples were examined using chemical analysis, x-ray diffraction, and mineral microscopy. Content Type Journal Article Pages 55-59 DOI 10.1007/s11837-011-0078-2 Authors Mira B. Cocić, Technical Faculty in Bor, University of Belgrade, Bor, Serbia Mihovil M. Logar, Faculty of Mining and Geology, University of Belgrade, Bor, Serbia Saša Lj. Cocić, Avala Resources, Bor, Serbia Snežana S. Dević, Institute IMS in Belgrade, Belgrade, Serbia Dragan M. Manasijević, Technical Faculty in Bor, University of Belgrade, Bor, Serbia Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 5

Description:    The formation of a block titanium sponge is considered in this paper on the basis of an analysis of the hydrodynamic flows in melted magnesium. It is suggested that the principal driving force in the organization of the flows in the melted magnesium is the zone of high temperature and pressure forming in the place of falling of jet titanium tetrachloride on the surface of melted magnesium. A presence of this zone causes the formation of a fan-shaped jet, which determines the process of forming the block titanium sponge. Content Type Journal Article Pages 66-68 DOI 10.1007/s11837-011-0080-8 Authors Aleksandr I. Putilin Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 5

Description: Molecular vibrational spectroscopy is an important method to study the atomic structure of graphene oxide. To investigate the effect of oxidation on the structural and spectroscopic properties of graphene, pseudo-potential density functional theory calculations were applied. Several models were considered, covering the most relevant functional groups that have been postulated to decorate the surface of graphene layer on carbon materials. Different arrangements of these units produced a range of vibrational spectra. The results suggested the possibility of creating and tuning graphene’s spectroscopic properties by varying the oxidation levels and the relative position of epoxy and hydroxyl functional groups on the surface. Spectra characteristics for local structures from this work shed light on the structural and vibrational properties of graphene oxide, which could be very helpful for experimental groups to further understand the structure of graphene oxide and reduce graphene oxide.

Description: Increasing the efficiency of natural gas reciprocating engines will require materials with better mechanical and corrosion resistance at high temperatures. One solution to increase the lifetime of exhaust valves is to apply an aluminide coating to prevent corrosion assisted fatigue cracking, but the impact of the coating on the valve material mechanical properties needs to be assessed. In addition to cyclic oxidation testing in dry and humid air at 800°C, creep and high cycle fatigue (HCF) testing were conducted at 816°C on bare and slurry or pack-coated 31V alloy. The coated and bare creep specimens exhibited very similar creep rupture lives, as long as the specimens were annealed according to the 31V standard heat treatment before testing. The HCF behavior of the pack-coated alloy was close to the behavior of the bare alloy, but fatigue lifetimes of slurry-coated 31V specimens had higher variability. Aluminide coatings have the potential to improve the valve performance at high temperature, but the coating deposition process needs to be tailored for the substrate standard heat treatment.

Description: Recent research on ancient ferrous artefacts belonging to different historical periods has indicated significant differences in various parameters characterizing the slags entrapped in these artefacts, in cases where they were obtained by using different production methods. Such differences have been observed by comparing “ancient period” artefacts with “subsequent period” artefacts. “Ancient period” products were obtained by direct reduction of iron ore, without carburizing and at temperatures below the melting point of the reduced sponge iron. In the “subsequent period”, the indirect process started to be introduced, with the production, in a first reduction stage, of a liquid cast iron that had to be converted to wrought iron during a second fining operation. The understanding of the characterizing parameters of the slags has in fact progressed to the point where they represent a useful tool not only for inferring the origins of the starting ore but also for distinguishing between direct or indirect production. In the present research work, an accurate study of the entrapped slags has been carried out on an artefact from the Val Gabbia III site, identified in previous studies as a miner’s chisel. This study aims to carry out further metallurgical investigation into the miner’s chisel microstructure and the entrapped slags in order to help ascertain which production method was in use at the Val Gabbia III site; in fact, based on the intrinsic characteristics of the chisel, and the fact that the site where it was found, i.e. layers of the V–VI cent AD in Val Gabbia III site, was characterized by the presence of an almost 3.5 kg cast iron block, previous investigators were led to suppose that it may be a very early site of indirect iron smelting. While the slag characterizing parameters obtained in the present investigation appear to be consistent with published results related to the direct method, the discussion on the relationship between the indirect method production effects on entrapped slag and the experimental findings substantiate, although not definitively, the hypothesis that the production method of the miner’s chisel is indirect.

Description: Integrated computational materials engineering (ICME) approaches to composition and thickness profiles of sputtered thin-film samples are the key to expediting materials exploration for these materials. Here, an ICME-based semi-empirical approach to modeling the thickness of thin-film samples deposited via magnetron sputtering is developed. Using Yamamura’s dimensionless differential angular sputtering yield and a measured deposition rate at a point in space for a single experimental condition, the model predicts the deposition profile from planar DC sputtering sources. The model includes corrections for off-center, tilted gun geometries as well as shadowing effects from gun chimneys used in most state-of-the-art sputtering systems. The modeling algorithm was validated by comparing its results with experimental deposition rates obtained from a sputtering system utilizing sources with a multi-piece chimney assembly that consists of a lower ground shield and a removable gas chimney. Simulations were performed for gun-tilts ranging from 0° to 31.3° from the vertical with and without the gas chimney installed. The results for the predicted and experimental angular dependence of the sputtering deposition rate were found to have an average magnitude of relative error of  \( 4.14\% \pm 3.02\% \) for a 0°–31.3° gun-tilt range without the gas chimney, and \( 2.12\% \pm 1.71\% \) for a 17.7°–31.3° gun-tilt range with the gas chimney. The continuum nature of the model renders this approach reverse-optimizable, providing a rapid tool for assisting in the understanding of the synthesis-composition-property space of novel materials.

Description: We report a scalable manufacturing approach to produce nano-porous metal oxide films and the dopant variants using a block-copolymer template combined with a sol–gel solution processing approach. The refractive index of the film can be tailored to 1.2–2.4 by 3D nanostructuring in the sub-wavelength regime at scales of 20 nm or less. Based on this approach, this paper reports the synthesis of nanoporous palladium (Pd)-doped titanium dioxide (TiO 2 ) film with refractive index matching the optical fiber material, and its importance on D-shaped fiber Bragg grating for hydrogen sensing at extremely high temperature up to 700°C. The sensor is based on evanescent field interaction in hydrogen-sensitive cladding. The flat side of D-shaped fiber grating was etched to remove a residual 4 μm cladding material, and thermally stabilized for high-temperature requirements. The peak intensity change of the fiber Bragg wavelength was observed with different hydrogen concentrations from 0.25 vol.% H 2 /N 2 to 5 vol.% H 2 /N 2 . The experimental result shows that the sensor’s hydrogen response is reversible and fast. The response time of the hydrogen sensor is 〈8 s.

Description: Phase-field crystal (PFC) is a model with atomistic-scale details acting on diffusive time scales. PFC uses the density field as its order parameter, which takes a constant value in the liquid phase and a periodic function in the solid phase. PFC naturally takes into account elasticity, solid–liquid interface free energy, surface anisotropy, and grain boundary free energy by using this single-order parameter in modeling of coexisting solid–liquid structures. In this article, the recent advancements in PFC modeling of materials nanostructures are reviewed, which includes an overview of different PFC models and their applications, and the numerical algorithms developed for solving the PFC governing equations. A special focus is given to PFC models that simulate coexisting solid–liquid structures. The quantitative PFC models for solid–liquid structures are reviewed, and the methods for determining PFC model parameters for specific materials are described in detail. The accuracy of different PFC models in calculating the solid–liquid interface properties is discussed.

Description: One key aspect of any integrated computational materials engineering approach is the integration of experiments that provide critical information for the modeling activities. This article describes, using case studies, three examples of critical experiments that have been conducted in an integrated fashion with modeling activities for titanium alloys, providing valuable information in an accelerated manner. The first has been used to identify key microstructural features associated with fracture toughness in Ti-6Al-4V and integrates artificial neural networks and various experimental techniques. The second is associated with defect accumulation in highly constrained titanium structures and integrates a highly innovative characterization technique (precession electron diffraction) and dislocation dynamics. The third is a high-throughput combinatorial technique to understand the oxidation behavior of titanium alloys and couples the experimental effort with the CALPHAD approach.

Description: Shaping lives, molding an industry: Symposium Honors the life and work of John T. Berry Content Type Journal Article Pages 100-100 DOI 10.1007/s11837-011-0020-7 Authors Lynne Robinson Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    To manufacture lightweight tube components for aerospace oil circuit systems, an experiment was run to investigate the deformation characteristics on Y-shaped tube hydroforming of 6061 aluminum alloy. Both strain state and metallurgical structure indicate that there are four kinds of prevailing defects during Y-shaped tube hydroforming: bursting, lack of cylindricity, wrinkling, and thinning due to the poor plastic property of 6061 aluminum alloy. The danger of bursting prevails at the early stage of the operation as a result of excessively high internal pressure. In contrast, wrinkling prevails after the middle stage of the operation as a result of excessively axial feeding and cannot be eliminated during subsequent deformation. Lack of cylindricity is mainly because of insufficient axial feeding and internal pressure but can be eliminated by increasing internal pressure. Elongation and compression deformations are originated on protrusion and main pipe of Y-shape tube respectively all the way through the bulging process. Consequently, minimum and maximum thicknesses are at the top of protrusion and the bottom of Y-shape tube respectively, which induces a V-shape borderline of thickness distribution. According to the excessive plastic deformation, microstructure evolution is originated. Crystal grain of protrusion is elongated and its grain size is about 150 μm. In contrast, crystal grain of the middle zone of main tube is refined greatly, which grain size is 50 μm, decreased by 75%. These are useful to improve the component. Content Type Journal Article Pages 81-84 DOI 10.1007/s11837-011-0034-1 Authors Guannan Chu, School of Naval Architecture, Harbin Institute of Technology at Weihai, Weihai, 264209 China Feng Li, College of Materials Science and Engineering, Harbin University of Science and Technology, Harbin, 150040 China Wenjian Liu, School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150001 China Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    A system consisting of piezoelectric transducers, arbitrary waveform generator, power amplifier, laser vibrometer, digital oscilloscope, and a computer has been constructed to study the nonlinear acoustic characteristics of fatigue microcracks of 2024-T351 aluminum alloy plates. Using two different frequency signals (f H =810 kHz, f L =100 kHz), the intact and microcracked samples are experimented, respectively. The experimental results show that in the intact samples there are only two fundamental frequencies and no harmonics and sidebands occur. In the microcracked samples, there is an abundance of the harmonics and sidebands, and the frequencies f H ±f L and f H ±2f L rise. These new frequency components can be used to indicate the presence of a microcrack or damage. Content Type Journal Article Pages 77-80 DOI 10.1007/s11837-011-0033-2 Authors G. L. Gao, Department of Material Science and Engineering, Harbin University of Science & Technology, Harbin, 150040 P.R. China D. Y. Li, Department of Material Science and Engineering, Harbin University of Science & Technology, Harbin, 150040 P.R. China D. Q. Shi, Department of Material Science and Engineering, Harbin University of Science & Technology, Harbin, 150040 P.R. China J. W. Dong, Department of Measurement-Control Technology & Communications Engineering, Harbin University of Science & Technology, Harbin, 150040 P.R. China X. D. Shi, Aeronautical Automation College, Civil Aviation University of China, Tianjin, 300300 P.R. China F. Teng, Department of Material Science and Engineering, Harbin University of Science & Technology, Harbin, 150040 P.R. China Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description: Opportunity analysis for MSE report defines pathway to a more sustainable energy future Content Type Journal Article Pages 30-34 DOI 10.1007/s11837-011-0024-3 Authors Lynne Robinson Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    The strain rate dependence of mechanical properties of AZ91D alloy composites filled with 5 wt.% hollow fly ash cenosphere is examined in the strain rate range of 630–1,203 s −1 using a split-Hopkinson pressure bar system. In addition, a test scheme is designed to study the intermediate strain rate response of the material. Addition of fly ash caused grain refinement and finer precipitates in the matrix alloy. Compared to the matrix alloy, the energy absorption is higher in AZ91D/fly ash cenosphere composites at comparable strain rates. In addition, the yield strength is found to be about 19–41% higher in the composites containing fly ash cenospheres. Content Type Journal Article Pages 48-52 DOI 10.1007/s11837-011-0028-z Authors Dung D. Luong, Composite Materials and Mechanics Laboratory, Mechanical and Aerospace Engineering Department, Polytechnic Institute of New York University, Brooklyn, NY 11201, USA Nikhil Gupta, Composite Materials and Mechanics Laboratory, Mechanical and Aerospace Engineering Department, Polytechnic Institute of New York University, Brooklyn, NY 11201, USA Pradeep K. Rohatgi, Center for Composite Materials, Materials Engineering Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    The effects of performing three twist extrusion passes on high purity aluminum samples were studied in this paper in regard to numerical analysis and experimental studies. The finite element analysis of the von-Mises stress and the equivalent plastic strain in the outer longitudinal and transverse cross-sections, which are parallel and normal to the billet axis respectively, was carried out. The simulation results showed that the end of the workpiece underwent more equivalent plastic strains in contrast to the head of the sample. Moreover, the corner regions experienced more strains than the center zone did. However, the heterogeneity in strain distribution in both longitudinal and transverse cross-sections decreased by performing the sequential twist extrusion passes. The experimental outcomes such as microstructure evolutions, microhardness and tensile tests validated the simulation results. Content Type Journal Article Pages 69-76 DOI 10.1007/s11837-011-0032-3 Authors Seyed Ali Asghar, School of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran, Iran Akbari Mousavi, School of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran, Iran Shahab Ranjbar Bahador, School of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran, P.O. Box: 11155-4563, Tehran, Iran Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description: The journal talks with 2010 TMS president George T. Gray III Content Type Journal Article Pages 19-20 DOI 10.1007/s11837-011-0022-5 Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    Titanium matrix syntactic foams have potential for orthopedic applications because of their good biocompatibility, corrosion resistance and ability of varying the elastic modulus. This paper studies the fabrication of Ti matrix syntactic foams embedded with ceramic microspheres (CMs) by a powder metallurgy method. The percentage of the crushed CMs during compaction was measured by the volume measurement and water absorption methods, and the elastic modulus of the Ti matrix syntactic foam was measured by compression tests. The effects of the Ti volume percentage and the compaction pressure on the percentage of crushed CMs and the elastic modulus were studied. For a given Ti volume percentage, the percentage of crushed CMs increases with increasing compaction pressure; for a given compaction pressure, the percentage of crushed CMs decreases with increasing Ti volume percentage. At a compaction pressure lower than 100 MPa, the elastic modulus increases with increasing Ti volume percentage and compaction pressure; at a compaction pressure above 100 MPa, further increases in Ti volume percentage and compaction pressure decrease the elastic modulus. Content Type Journal Article Pages 43-47 DOI 10.1007/s11837-011-0027-0 Authors Xiaobing Xue, School of Engineering, University of Liverpool, L69 3GH Liverpool, UK Yuyuan Zhao, School of Engineering, University of Liverpool, L69 3GH Liverpool, UK Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description:    The strain rate dependence of compressive response is determined for aluminum alloy/hollow fly ash cenosphere composites. A4032 alloy is used as the matrix material. Quasi-static and high strain rate compression tests are conducted on the matrix alloy and the composite. A split-Hopkinson pressure bar is used for high strain rate testing. While the matrix alloy does not show any appreciable strain rate sensitivity, the composite shows higher strength at higher strain rates. The energy absorption capability of A4032/fly ash cenosphere composites is found to be higher at higher strain rates. Content Type Journal Article Pages 53-56 DOI 10.1007/s11837-011-0029-y Authors Dung D. Luong, Composite Materials and Mechanics Laboratory, Mechanical and Aerospace Engineering Department, Polytechnic Institute of New York University, Brooklyn, NY 11201, USA Nikhil Gupta, Composite Materials and Mechanics Laboratory, Mechanical and Aerospace Engineering Department, Polytechnic Institute of New York University, Brooklyn, NY 11201, USA Atef Daoud, Central Metallurgical Research and Development Laboratory, Helwan, Cairo, Egypt Pradeep K. Rohatgi, Materials Engineering Department, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description: 2011 TMS president Garry Warren: Looking ahead to a productive year Content Type Journal Article Pages 18-18 DOI 10.1007/s11837-011-0021-6 Authors Garry Warren Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2

Description: Metal matrix syntactic foams: Manufacture, matrix material, microstructure, modulus and more Content Type Journal Article Pages 35-35 DOI 10.1007/s11837-011-0025-2 Authors Yuyuan Zhao Journal JOM Journal of the Minerals, Metals and Materials Society Online ISSN 1543-1851 Print ISSN 1047-4838 Journal Volume Volume 63 Journal Issue Volume 63, Number 2