As a fundamentally different process for creation of complex parts, laser powder bed fusion (LPBF) additive manufacturing exhibits complex behavior at the melt pool that has a direct influence on the macroscopic properties of the final material. Powder denudation, a previously studied deleterious phenomenon, is the displacement of powder due to entrainment in a jet of rapidly vaporized metal created by the process laser. To minimize the effect of denudation and inspired by methods in adjacent fields, a laser pre-sintering (LPS) method was studied in an effort to reduce denudation. LPS was found to be most effective in the 1–4 J/mm³ volumetric energy density processing regimes, minimizing the common experimentally observed problems with the LPBF process. Scanning electron microscopy of the LPS-treated powder bed revealed insight into the accelerating effect morphological irregularities along the powder particle surface have in the pre-sintering process. To further understand the process, an estimation of the sintered neck sizes necessary to eliminate denudation in LPS is made, qualitatively affirming the low energy densities needed to prevent denudation. The results presented in this work represent an initial step towards understanding and implementing LPS as a quality-enhancing step in LPBF.

作为制造复杂零件的根本不同的过程，激光粉末床熔合（LPBF）增材制造在熔池处表现出复杂的行为，这直接影响了最终材料的宏观性能。粉末剥蚀是一种以前研究过的有害现象，是由于夹带在过程激光产生的快速汽化金属射流中而引起的粉末位移。为了最大程度地减少剥蚀的影响并受到相邻领域方法的启发，研究了激光预烧结（LPS）方法以减少剥蚀。发现LPS在1–4 J / mm ^3下最有效体积能量密度处理方案，最大程度地减少了LPBF工艺在实验中观察到的常见问题。经LPS处理的粉末床的扫描电子显微镜揭示了对预烧结过程中沿粉末颗粒表面形态不规则现象的加速作用的见解。为了进一步理解该过程，对消除LPS剥蚀所需的烧结颈尺寸进行了估算，从质上肯定了防止剥蚀所需的低能量密度。这项工作中提出的结果是迈向理解和实施LPS的第一步，这是LPBF中提高质量的步骤。