目的 优化IN939镍基高温合金涂层的组织与性能。方法 采用同轴送粉激光熔覆技术制备了IN939涂层，并将涂层分成四组，一组作为对照，其余三组分别采用单固溶处理、单时效处理、完全热处理（固溶+时效）。通过光学显微镜（OM）、扫描电子显微镜（SEM）和X射线衍射仪（XRD），分析了显微组织结构和物相组成，并通过显微硬度测试、电化学腐蚀试验来研究热处理过程中涂层组织的变化对硬度和耐蚀性能的影响。结果 激光熔覆IN939高温合金涂层的形貌良好，并且没有出现气孔、裂纹等缺陷。热处理前试样中很难观察到γ′相，而三组热处理后的试样中均出现了γ′相沉淀，其中单固溶处理后析出的γ′颗粒的平均粒径为60 nm，而单时效和完全热处理所析出的γ′颗粒的平均粒径为100 nm。热处理后涂层显微硬度有所提高，其中单时效后的涂层平均硬度为472.7HV0.2，比热处理前提高了10.2%；完全热处理后的涂层平均硬度为475.6HV0.2，比热处理前提高了10.9%。此外，电化学腐蚀试验结果显示，单时效处理和完全热处理后的IN939涂层的自腐蚀电流密度明显减小（分别为3.014×10–7、3.441×10–7 A/cm2），使得极化电阻分别提高了35.1%和39.3%，腐蚀速率大大降低。结论 热处理能够使激光熔覆IN939涂层中的γ′相析出，单时效与完全热处理过程中γ′相的析出方式不同，但最终的尺寸和分布基本一致。热处理可以提高涂层的硬度和耐蚀性能，其中完全热处理对性能的提升最明显，单时效处理次之。

The work aims to optimize the microstructure and performance of IN939 nickel-based superalloy coating. Coaxial powder feeding laser system was used to prepare IN939 coatings and the coatings were divided into four groups: one group was used as the control group and the other three groups respectively underwent solution treatment, aging treatment and complete heat treatment (solution + aging). The microstructure and phase composition were analyzed by optical microscope (OM), scanning electron microscope (SEM) and X-ray diffraction (XRD). The effects of heat treatment on hardness and corrosion resistance of the coatings were studied by microhardness test and electrochemical corrosion test. Laser cladded IN939 superalloy coatings had good morphology, without defects such as pores and cracks. Before heat treatment, γ′ precipitation was hardly found in the coating, but γ′ precipitation appeared in the three groups of coatings after heat treatment. Furthermore, the average size of γ′ particles precipitated after solution treatment was about 60 nm, while that after aging treatment and complete heat treatment was about 100 nm. In addition, the hardness of the coating was improved after the heat treatments. The average hardness of the coating after aging treatment was 472.7HV0.2, which was 10.2% higher than that before heat treatment. The average hardness of the coating after complete heat treatment was 475.6HV0.2, which was 10.9% higher than that before heat treatment. The electrochemical corrosion test results showed that the current density values of the IN939 coating after single aging treatment and complete heat treatment were much smaller (3.014×10-7 A/cm2, 3.441×10-7 A/cm2, respectively) and the polarization resistance of the coating was increased by 35.1% and 39.3%, respectively, greatly reducing the corrosion rate. Heat treatment can precipitate γ′ phase in laser cladded IN939 coating, and the size and distribution of γ′ particles precipitated via aging treatment and complete heat treatment are basically the same. Additionally, heat treatment can improve the hardness and corrosion resistance of the coating. The complete heat treatment has the most obvious improvement on the performance of the coating, followed by single aging treatment.