目的 研究采用IN939粉材对镍基高温部件增材修复的可行性，获得增材修复区微观组织与性能分布规律，为燃机部件修复提供支持。方法 探索了IN939合金激光熔覆成形工艺，并进一步开展了IN939增材修复镍基合金梯形槽试验研究，分析了增材修复区显微组织结构与物相组成，研究了激光再制造过程组织变化对修复区显微硬度、拉伸性能的影响。结果 IN939激光修复区形貌良好，组织致密，无明显裂纹、气孔等缺陷。熔覆层主要存在γ奥氏体相和Laves相。IN939修复区由底部至顶部，冷却速率逐渐减小，导致一次枝晶间距逐渐增大，Laves相分布先增多后略有减小。修复区界面处的平均横向残余拉应力为346 MPa。修复区显微硬度由底部至顶部呈现先增大后略有减小的趋势，修复区的平均显微硬度强于基体。修复件的平均屈服强度为548 MPa，极限抗拉强度为959 MPa。激光修复件的拉伸断裂于基体上，显示出IN939合金与基体良好的冶金结合。结论 激光增材修复后，IN939镍基合金修复区的机械性能与结合性能良好，采用IN939粉材进行镍基高温合金的激光增材修复具备可行性。

The feasibility of repairing nickel-based superalloy components by IN939 powder was verified and the microstructure and properties of the repaired zone were investigated in this study so as to provide support for the repair of gas turbine components. The laser cladding process of IN939 alloy was explored, and the laser additive repairing of trapezoidal groove in nickel-based alloy using IN939 was carried out. The microstructure and the phase composition of additively repaired zone were characterized. Furthermore, the effects of microstructure evolution during the repairing on the repaired zone properties were investigated by micro-hardness tests and tensile tests. The results showed that the repaired zone of IN939 was dense and had good morphology without significant defects like cracks, pores. There are the γ-austenite phase and the Laves phase in IN939 cladding layer. From the bottom of the layer to the top, the cooling rate of the cladding layer decreases leading to increase of the primary dendrite spacing, while the Laves phase increases at first and then decreases. The average horizontal tensile residual stress at the interface was 346 MPa. From the bottom of the repaired zone to the top, the microhardness increases at first and then decreases. The average microhardness of the repaired zone was higher than the substrate. The average yield strength of the repaired samples is 548 MPa, and the ultimate tensile strength is 959 MPa. The tensile failure occurred in the substrate, showing a good metallurgical bond between the IN939 alloy and the substrate. The IN939 repaired zone has high mechanical properties and bonding properties after laser additive repairing, verifying the feasibility of laser additive repairing with IN939 powder.