[T1] Powder Production

[15C-T1-26] The changes of rheological behavior of Ti-6Al-4V alloy powders for additive manufacturing by powder oxidation

*N. Kakegawa¹, W. Zhou¹, N. Nomura1 (1.Tohoku University, Japan)

Keywords:Laser powder bed fusion, Ti-6Al-4V alloy powders, Oxidation, Powder rheological behavior, Cohesive strength

Laser powder bed fusion (L-PBF) has recently attracted increasing attention as a method for fabricating three-dimensional metallic parts with complex structures. For energy saving and cost reduction, the reuse of feedstock powders has been recommended in L-PBF. However, the surface of powders is usually oxidized due to the existence of residual oxygen in building chamber during L-PBF process. The effect of oxidation on the powder flowability is unknown.Therefore, by taking Ti-6Al-4V alloy powder as a model material, it was intentionally heat-treated in air, Ar atmosphere, and oxidized by H2O2 treatment. Subsequently, the relationship between powder oxidation and flowability was experimentally investigated and clarified.