Development of a Process to Manufacture Spherical Nanoreinforced Titanium Alloy Powders for Additive Manufacturing

摘要

Reinforcing titanium alloy powders with ceramic nanoparticles is an attractive way to improve its strength, stiffness and wear resistance. Additive Manufacturing (AM) technologies require powders with good packing and flowability characteristics. This work describes a method to produce such powders. Ti-6Al-4V wt% (Ti64) powders were mixed with ceramic nanoparticles following different procedures. Mixing method is important to control pick-up of oxygen, carbon and nitrogen, as well as to break nanoparticles agglomerates. Next, the obtained powder was consolidated into a bar of about 400 mm in length and 40 mm in diameter by Hot Isostatic Pressing (HIP). Finally, this bar was used as feedstock for Electrode Induction Melting Gas Atomisation (EIGA). In this way, it was produced a Ti64 powder reinforced with titanium carbide or yttria nanoparticles, with spherical particle shape, and high relative apparent and tap densities.