采用激光选区熔化（SLM）工艺成形GH5188合金，研究激光功率、扫描速度、扫描间距和层间转角等制备参数对成形质量的影响，并进行了力学性能和微观组织分析。结果表明：激光功率为200 W、扫描速度为800 mm/s、扫描间距为0.08 mm、层间转角为45°时成形试样内部组织均匀性优于表面、顶面质量优于侧面。基体组织形貌受熔池熔道影响，细晶分布在熔道边缘，晶粒内存在细小亚晶（粒径为1~2 μm）和长条状析出碳化物M₂₃C₆/M₆C（长约50 nm、宽约10 nm），碳化物颗粒弥散分布于基体中，亚晶阻碍位错运动及碳化物对位错具有钉扎作用，强化了GH5188合金的力学性能。该工艺参数下试样致密度可达98.75%，硬度达296.71 HV，抗拉强度为1 048.38 MPa，硬度和抗拉性能大于热轧板，延伸率为11.7%，低于热轧板，SLM成形的GH5188合金呈现较好的力学性能。

The effects of laser power， scanning speed， scanning distance and interlayer angle on the forming quality of GH5188 alloy were investigated by Selective Laser Melting （SLM） process. The microstructure and mechanical properties were analyzed. The results show that when the laser power is 300 W， the scanning speed is 800 mm/s， the scanning spacing is 0.08 mm， and the print direction angle between layers is 45°， the internal microstructure of the formed sample is better than the surface， and the quality of the top surface is better than that of the side surface. The microstructure of the alloy is affected by the weld channel and molten pool， and the fine crystals are distributed on the edge of the weld channel. There are fine subcrystals （diameter is 1–2 μm） and long strip precipitation carbide M₂₃C₆/M₆C （about 50 nm long and 10 nm wide） in the grains， and the carbide particles are uniformly dispersed in the matrix. The movement of dislocation was hindered by the subcrystals， and the carbides have pinning effect on dislocation， strengthening the mechanical properties of GH5188 alloy. Under the process parameters， the density of GH5188 alloy increased to 98.75%， the hardness is 296.71 HV， and the tensile strength is 1 048.38 MPa. The hardness and tensile properties of the sample are higher than that of the hot rolled plate， and the elongation is 11.7%， which is lower than that of the hot rolled plate. GH5188 alloy fabricated by SLM has good mechanical properties.