INCONEL系镍基高温合金选区激光熔化增材制造工艺研究

Study on Selective Laser Melting Additive Manufacturing Process of INCONEL Ni-based Superalloy

研究了激光加工工艺参数对选区激光熔化工艺成形的Inconel 718合金试样的致密化行为、显微组织特征、硬度及摩擦磨损性能的影响。结果表明:当激光线能量密度(η)较低时,球化效应的出现使试样的致密度水平较低;在较高的线能量密度与合适的加工参数下,可获得接近完全致密的Inconel 718合金试样。同时,随着激光线能量密度的增加,SLM成形Inconel 718合金试样的显微组织经历了粗大的柱状树枝晶、聚集的枝晶、细长而均匀分布的柱状枝晶等变化过程。在优化工艺参数下,成形试样的显微硬度高达397.8 HV0.2;摩擦系数和磨损率较低,分别为0.40和4.78×10-4mm3/Nm;且试样内部显微组织均匀细小,摩擦试样的表面形成摩擦保护层,使试样的摩擦磨损性能较好。

Influence of the process parameters on densilication behavlor,mlcrostructure characteristics,microhardness and wear performance of SLM-processed Inconel 718 alloy samples was studied comprehensively. The result shows that at a lower laser linear energy density （η）,the bailing effect caused a low densification level. At a higher value of laser energy density with reasonable process parameters,nearly full dense lnconel 718 part was obtained. Besides,as laser energy density increased,microstructures of Inconel 718 parts experienced such changes：coarsened columnar dendrites,clustered dendrites,slender and uniformly distributed columnar dendrites. Samples manufactured at optimized process parameters exhibited high microhardness of 397.8 HV02,1ow mean COF value of 0.40 and low wear rate of 4.78×10^-4 mma/Nm. The formation of fine microstructure and the protective tribolayer gave the sample good wear performance.