[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 Fuson (L-PBF), Ti-6Al-4V powders, Flowability, Powder oxidation

Laser powder bed fusion (L-PBF) has recently attracted significant 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 for L-PBF. However, it is reported that the powder surface is usually oxidized during L-PBF process. Even though the influence of oxygen content on the mechanical properties of L-PBF builds has been investigated by some researchers, the effect of surface oxidation on the powder flowability is still controversial. Therefore, by taking Ti-6Al-4V alloy powder as a model material, it was intentionally oxidized via the wet mixing process with aqueous hydrogen peroxide. Subsequently, the relationship between powder oxidation and flowability was experimentally investigated and clarified. The powders were successfully oxidized by the wet mixing process without changing their morphology or particle size distribution, but the oxidized powders had better flowability rather than the raw powders.