Making laser powder bed fusion (L-PBF) additive manufacturing process sustainable requires effective powder recycling. Recycling of Ti6Al4V powder in L-PBF can lead to powder oxidation, however, such impact on laser-matter interactions, process, and defect dynamics during L-PBF are not well understood. This study reveals and quantifies the effects of processing Ti6Al4V powders with low (0.12 wt%) and high (0.40 wt%) oxygen content during multilayer thin-wall L-PBF using in situ high speed synchrotron X-ray imaging. Our results reveal that high oxygen content Ti6Al4V powder can reduce melt ejections, surface roughness, and defect population in the built parts. With increasing oxygen content in the part, there is an increase in microhardness due to solid solution strengthening and no significant change in the microstructure is evident.

要使激光粉末床熔融 (L-PBF) 增材制造工艺可持续，需要有效的粉末回收。在 L-PBF 中回收 Ti6Al4V 粉末会导致粉末氧化，然而，L-PBF 过程中对激光与物质相互作用、过程和缺陷动力学的影响尚不清楚。这项研究揭示并量化了在原位多层薄壁 L-PBF 过程中加工低氧含量 (0.12 wt%) 和高氧含量 (0.40 wt%) Ti6Al4V 粉末的影响高速同步加速器 X 射线成像。我们的结果表明，高氧含量的 Ti6Al4V 粉末可以减少成型零件中的熔体喷射、表面粗糙度和缺陷数量。随着零件中氧含量的增加，由于固溶强化，显微硬度增加，但显微组织没有明显变化。