【摘要】 激光选区熔化(Selective Laser Melting, SLM)通过激光能量使金属粉末按照规划路径加热熔化再冷却凝固形成增材制造零件，在粉末熔化过程中由于激光工艺参数设置不合理会引起零件致密度下降并在表面层产生过大的残余应力，对增材制造零件的后续加工及其服役应用造成不利影响。为预测与抑制SLM过程中发生的残余应力，研究SLM激光能量密度参数和工艺参数(包括激光功率、扫描速度和扫描间距)对增材制造316L不锈钢零件致密度与残余应力的影响，并优化工艺参数以提高增材制造零件的力学性能。研究结果表明，改变激光能量密度对增材制造零件致密度与残余应力均有较大影响，能量密度与零件表面层残余应力呈正相关关系，但能量密度过小会引起致密度下降，降低零件的服役寿命。更多还原

【Abstract】 Selective laser melting involves laser to heat and melt metal powder along a pre-defined path, followed by rapid cooling to solidify, resulting in the formation of additively manufactured parts. During the powder melting process, the improper configuration of laser and process parameters can lead to a reduction in part density and the excessive generation of residual stresses in the surface layer. These issues have an adverse impact on the subsequent post-processing and operational applications of additively manufactured parts. To predict and mitigate the occurrence of residual stresses in the selective laser melting additive manufacturing process, this study investigates the influence of SLM laser energy density parameters and process parameters, including laser power, scanning speed and scan spacing, on the density and residual stress of 316L stainless steel parts, and the process parameters are optimized to improve the mechanical properties of additive manufacturing parts. The research findings indicate that altering the laser energy density has a significant impact on both the density and residual stresses of additively manufactured parts.Energy density exhibits a positive correlation with residual stresses in the surface layer of the parts. However, excessively low energy density can result in decreased density, ultimately reducing the service life of the parts.更多还原