Publication Date:
2011-06-21
Description:
Microstructures and a microstructural, columnar architecture as well as mechanical behavior of as-fabricated and processed INCONEL alloy 625 components produced by additive manufacturing using electron beam melting (EBM) of prealloyed precursor powder are examined in this study. As-fabricated and hot-isostatically pressed (“hipped”) [at 1393 K (1120 °C)] cylinders examined by optical metallography (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive (X-ray) spectrometry (EDS), and X-ray diffraction (XRD) exhibited an initial EBM-developed γ ″ (bct) Ni 3 Nb precipitate platelet columnar architecture within columnar [200] textured γ (fcc) Ni-Cr grains aligned in the cylinder axis, parallel to the EBM build direction. Upon annealing at 1393 K (1120 °C) (hot-isostatic press (HIP)), these precipitate columns dissolve and the columnar, γ , grains recrystallized forming generally equiaxed grains (with coherent {111} annealing twins), containing NbCr 2 laves precipitates. Microindentation hardnesses decreased from ~2.7 to ~2.2 GPa following hot-isostatic pressing (“hipping”), and the corresponding engineering (0.2 pct) offset yield stress decreased from 0.41 to 0.33 GPa, while the UTS increased from 0.75 to 0.77 GPa. However, the corresponding elongation increased from 44 to 69 pct for the hipped components. Content Type Journal Article Pages 1-18 DOI 10.1007/s11661-011-0748-2 Authors L. E. Murr, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA E. Martinez, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA S. M. Gaytan, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA D. A. Ramirez, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA B. I. Machado, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA P. W. Shindo, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA J. L. Martinez, Department of Metallurgical and Materials Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA F. Medina, W.M. Keck Center for 3D Innovation, The University of Texas at El Paso, El Paso, TX 79968, USA J. Wooten, CalRAM, Inc., Simi Valley, CA 93065, USA D. Ciscel, CalRAM, Inc., Simi Valley, CA 93065, USA U. Ackelid, Arcam AB, Mölndal, SE-431-37 Sweden R. B. Wicker, W.M. Keck Center for 3D Innovation, The University of Texas at El Paso, El Paso, TX 79968, USA Journal Metallurgical and Materials Transactions A Online ISSN 1543-1940 Print ISSN 1073-5623
Electronic ISSN:
1543-1940
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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