Investigation of Microstructure and Mechanical Properties for Ti-6Al-4V Alloy Parts Produced Using Non-Spherical Precursor Powder by Laser Powder Bed Fusion

Jaime Varela; Edel Arrieta; Muktesh Paliwal; Mike Marucci; Jose H Sandoval; Jose A Gonzalez; Brandon McWilliams; Lawrence E Murr; Ryan B Wicker; Francisco Medina

doi:10.3390/ma14113028

Investigation of Microstructure and Mechanical Properties for Ti-6Al-4V Alloy Parts Produced Using Non-Spherical Precursor Powder by Laser Powder Bed Fusion

Materials (Basel). 2021 Jun 2;14(11):3028. doi: 10.3390/ma14113028.

Authors

Jaime Varela^{1

2}, Edel Arrieta^{1

2}, Muktesh Paliwal³, Mike Marucci³, Jose H Sandoval⁴, Jose A Gonzalez⁴, Brandon McWilliams⁵, Lawrence E Murr^{2

6}, Ryan B Wicker^{1

2}, Francisco Medina^{1

2}

Affiliations

¹ Department of Mechanical Engineering, The University of Texas at El Paso, El Paso, TX 79938, USA.
² W.M. Keck Center for 3D Innovation, University of Texas at El Paso, El Paso, TX 79968, USA.
³ Kymera International-Reading Alloys, Robesonia, PA 19551, USA.
⁴ Lockheed Martin Missiles and Fire Control, Dallas, TX 75051, USA.
⁵ CCDC Army Research Laboratory, Aberdeen Proving Ground, MD 21005, USA.
⁶ Department of Metallurgical, Materials and Biomedical Engineering, The University of Texas at El Paso, El Paso, TX 79968, USA.

Abstract

An unmodified, non-spherical, hydride-dehydride (HDH) Ti-6Al-4V powder having a substantial economic advantage over spherical, atomized Ti-6Al-4V alloy powder was used to fabricate a range of test components and aerospace-related products utilizing laser beam powder-bed fusion processing. The as-built products, utilizing optimized processing parameters, had a Rockwell-C scale (HRC) hardness of 44.6. Following heat treatments which included annealing at 704 °C, HIP at ~926 °C (average), and HIP + anneal, the HRC hardnesses were observed to be 43.9, 40.7, and 40.4, respectively. The corresponding tensile yield stress, UTS, and elongation for these heat treatments averaged 1.19 GPa, 1.22 GPa, 8.7%; 1.03 GPa, 1.08 GPa, 16.7%; 1.04 GPa, 1.09 GPa, 16.1%, respectively. The HIP yield strength and elongation of 1.03 GPa and 16.7% are comparable to the best commercial, wrought Ti-6Al-4V products. The corresponding HIP component microstructures consisted of elongated small grains (~125 microns diameter) containing fine, alpha/beta lamellae.

Keywords: hydride-dehydride (HDH) Ti-6Al-4V powder; laser powder bed fusion; mechanical properties; microstructure; non-spherical; post-process heat treatment.