Production of Low-cost Spherical Ti Alloy Powder for Additive Manufacturing

A novel method is developed to produce spherical Ti alloy powders for additive manufacturing (AM) applications. The new process synergistically integrates a few common low-cost steps including granulation, sintering, and deoxygenation to produce spherical Ti alloy powders without relying on costly melting and atomizing techniques. This granulation-sintering-deoxygenation (GSD) process uses low-cost source materials such as hydrogenated Ti sponge and Ti scrap as raw materials, and it also has a very high yield of fine powder (-325 mesh). The spherical Ti-6Al-4V powder produced by the GSD method has excellent flowability and low oxygen content (<0.15%), which meets physical and chemical requirements for AM applications. The GSD Ti-6Al-4V powder was compared commercial spherical powders in selective laser melting (SLM). It showed that the tensile property of SLM parts from low-cost GSD powder was essentially the same with that of parts printed from other commercial spherical powders.