目的 研究超声振幅对激光熔覆WC陶瓷颗粒在熔池凝固过程中流动特性的影响，在IN718镍基高温合金表面制备出硬度高和高温耐磨性良好的WC/IN718金属基陶瓷涂层。方法 采用VHX-1000型超景深显微镜，观察不同超声振幅作用下WC陶瓷颗粒在复合涂层横截面的分布规律；借助于光学显微镜（OM）、扫描电镜（SEM）、X射线衍射仪（XRD）等设备，表征不同超声振幅下复合涂层显微组织与物相组成；采用显微硬度仪和旋转式高温摩擦磨损试验机，研究不同超声振幅下复合涂层的显微硬度和高温耐磨性能。结果 当超声振幅为22 μm时，复合涂层平均显微硬度最大（562HV0.2），相对未施加超声的复合涂层提高了49.9%，抗高温摩擦系数（0.4）相对未施加超声的复合涂层（0.6）降低了67.0%。复合涂层的磨损机制为氧化磨损和轻微的磨粒磨损。结论 由于超声场对激光熔覆过程的声流强化效应和空化效应的影响，促使WC陶瓷颗粒在熔池中逐渐上浮，消除了熔池底部WC颗粒的沉积效应。超声场的热效应使WC颗粒在熔池中的溶解率有所增加，复合涂层的稀释率也相应得到提高。施加超声场的复合涂层的平均显微硬度和高温耐磨性得到明显提升。

The work aims to study the effect of ultrasonic amplitude on the flow characteristics of laser cladding WC ceramic particles during the solidification process in the molten pool, so as to prepare WC/IN718 cermet coating with high hardness and good high temperature wear resistance on the surface of IN718 nickel base superalloy. The distribution of WC ceramic particles in the cross section of composite coating under different ultrasonic amplitudes was observed by VHX-1000 superfield microscope. The microstructure and phase composition of the composite coating were characterized by OM, SEM and XRD. The microhardness and high temperature wear resistance of the composite coating under different ultrasonic amplitudes were studied by microhardness tester and rotary high temperature friction and wear tester. When the ultrasonic amplitude was 22 μm, the average microhardness of the composite coating was the highest (562HV0.2), 49.9% higher than that of coating without ultrasonic application, and the high temperature friction coefficient (0.4) of the composite coating was 67.0% lower than that of coating without ultrasonic application (0.6). The wear mechanism of the composite coating was oxidation wear and slight abrasive wear. Due to the influence of ultrasonic field on the acoustic flow strengthening and cavitation effect in the laser cladding process, WC ceramic particles gradually float up in the molten pool, eliminating the deposition effect of WC particles at the bottom of the molten pool. In addition, due to the thermal effect of the ultrasonic field, as the dissolution rate of WC particles in the molten pool increases, the dilution rate of the composite coating also increases accordingly. The average microhardness and high temperature wear resistance of the composite coating applied with the ultrasonic field are significantly improved.