利用选区激光熔化技术制备GH4169试样, 采用光学显微镜、扫描电子显微镜、电子万能材料试验机分别分析了成型件的宏观及微观组织形貌和力学性能。结果表明, 选区激光熔化成型件的结晶形貌主要为胞状结晶形态, “微熔池”内部的细小的柱状晶直径约为0.1～1.0 μm, 截面成近似六角形的形状; 选区激光熔化过程中, 由于激光照射角度不同、铺粉不均匀、温度累积及散热条件的变化, “微熔池”内部细小柱状晶的形状、长度、宽度会有所差别; 选区激光熔化GH4169成型件拉伸试样呈现韧性断裂+解理断裂模式。

GH4169 samples were prepared by selective laser melting technique. The macroscopic and microscopic structure morphology and mechanical properties of the manufactured parts were analyzed by optical microscope, scanning electron microscope and electronic universal material testing machine. The results show that the crystal morphology of SLM molded parts is mainly cellular crystal, the diameter of fine columnar crystal is about 0.1～1.0 μm inside the "micro-melting pools", and the cross section is approximate hexagonal shape. Due to the different angles of laser incidence, powder uneven, temperature accumulation and change in heat dissipation conditions during the SLM process, the shape, length, width of the columnar crystal is different in the "micro-melting pools". The tensile specimens of SLM GH4169 molded parts present ductile fracture + cleavage fracture mode.