ABSTRACT

The laser-powder bed fusion (L-PBF), also known as selective laser melting (SLM), is widely processed to a narrow powder size of 15 (D₁₀) to 45 (D₉₀) µm. However, expanding the particle size distribution (PSD) that can be processed by L-PBF can have important technical and economic benefits. Using 420 stainless steel as a case study, the current investigation successfully shows that finer particles can also be successfully processed by L-PBF to achieve comparable tensile strength, corrosion resistance, microstructure and density. The results of the study determined that agglomeration of fine powders was the critical barrier that previously limited successful processing. Further, the study clearly showed that a simple and scalable vibratory sieving process was sufficient to deagglomerate the fine powder to improve flowability and achieve consistent printability of engineering parts.

摘要

激光-粉末床熔合 (L-PBF)，也称为选择性激光熔化 (SLM)，被广泛加工成 15 (D ₁₀ ) 到 45 (D _{90 ) 的窄粉末尺寸}) 微米。然而，扩大 L-PBF 可处理的粒度分布 (PSD) 具有重要的技术和经济效益。以 420 不锈钢为例，目前的研究成功地表明，L-PBF 也可以成功加工更细的颗粒，以达到相当的抗拉强度、耐腐蚀性、微观结构和密度。研究结果确定，细粉末的团聚是以前限制成功加工的关键障碍。此外，该研究清楚地表明，简单且可扩展的振动筛分工艺足以解聚细粉末以提高流动性并实现工程部件的一致印刷性。