Metallic powder reuse presents attractive economic and environmental advantages for direct metal laser sintering (DMLS). However, continuous recycling of powder raises concerns of powder quality and sintered part performance, and complicates process validation. Efforts to examine the mechanical response of parts built with reused feedstocks are increasingly common in the technical literature, but none have optimized process parameters in DMLS to control for changes in material properties. In this paper, titanium powder reuse was investigated with the objective of optimizing the additive manufacturing (AM) process for reuse. Virgin Ti-6Al-4V powder was cycled a total of eight times through conditions representative of industrial DMLS machines. A full 2³-factorial design of experiments (DOE) approach was employed to identify how parameter settings affect mechanical behavior, and include reuse as a process variable. The independent factors (laser power, laser speed, and hatch distance) did not significantly affect mechanical properties; however, measurements of ductility were found to be influenced by some interaction between the factors. These results were attributed to the narrow operating envelope which was required for successfully sintered specimens. Density and chemistry measurements further demonstrated no significant change with respect to reuse. The findings suggest that titanium powder can be reused up to eight times without any noticeable loss in strength or ductility.

金属粉末的再利用为直接金属激光烧结（DMLS）带来了诱人的经济和环境优势。然而，粉末的连续回收引起对粉末质量和烧结零件性能的关注，并使过程验证复杂化。在技​​术文献中，越来越多地尝试检查使用可重复使用的原料制造的零件的机械响应，但是没有一种在DMLS中优化工艺参数来控制材料性能的变化。本文研究了钛粉的再利用，目的是优化增材制造（AM）的再利用工艺。在代表工业DMLS机器的条件下，维珍Ti-6Al-4V粉末共循环八次。整场2 ³实验的因子设计（DOE）方法用于确定参数设置如何影响机械行为，并将重用作为过程变量。独立的因素（激光功率，激光速度和舱口距离）不会显着影响机械性能。但是，延展性的测量结果受这些因素之间某些相互作用的影响。这些结果归因于成功烧结样品所需的狭窄工作范围。密度和化学测量结果进一步表明，再利用方面没有显着变化。研究结果表明，钛粉可以重复使用多达八次，而强度或延展性却没有明显降低。