目的 改善传统激光熔覆涂层中常出现的气孔和裂纹等缺陷，提高涂层整体质量和使用性能。方法 首先利用粘接剂将镍包WC合金粉末预置于Q235基体材料上，采用正交试验得到的最优参数（激光功率P=1600 W，光斑直径d=5 mm，扫描速度ν=4 mm/s）进行熔覆试验，整个熔覆过程使用20 kHz的超声波发生器，以空气为载体，向激光熔池中同步施加超声振动，然后分别使用扫描电子显微镜（SEM）、能谱仪（EDS）、X射线衍射仪（XRD）、显微硬度仪及万能摩擦磨损试验机（UMT），对涂层的显微组织、元素成分及物相、显微硬度和耐磨性能进行测量分析。结果 施加超声振动后涂层的晶粒更加细小，主要由细小等轴晶和少量枝晶组成，涂层中气孔和裂纹明显减少，Cr、Ni、W、C等元素分布趋于均匀，涂层物相主要由固溶体γ-(Ni, Fe)、金属间化合物Ni3Fe、WC、Cr23C6等组成。施加超声振动后涂层平均显微硬度为937HV，与未施加超声振动的涂层相比提高了13%，摩擦系数为0.43，降低了约26%，耐磨性能提高了44%。结论 利用空载式超声振动辅助激光熔覆，可使制备出的涂层质量显著改善，微观组织更加致密，硬度、耐磨性得到提升。

The work aims to eliminate the defects such as pore and crack in traditional laser cladding coatings, and improve the overall quality and performance of coatings. Nickel-coated WC alloy powders were pre-placed on Q235 matrix by adhesive and the cladding test was carried out with the optimum parameters obtained through orthogonal test (laser power P=1600 W, spot diameter d=5 mm, scanning speed ν=4 mm/s). During the whole cladding process, a 20 kHz ultrasonic generator was used to synchronously apply ultrasonic vibration to the laser pool with air as the carrier. Then, the microstructure, element composition, phase, microhardness and wear resistance of the coatings were measured and analyzed by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), microhardness tester and universal friction and wear tester (UMT). The grains of the dynamic coatings by ultrasonic vibration were finer and mainly consisted of fine equiaxed grains and columnar grains. The pores and cracks in such coatings were obviously reduced. Elements such as Cr, Ni, W, and C tended to be distributed uniformly. The coating was mainly composed of solid solution γ-(Ni,Fe), intermetallic compound Ni3Fe, WC, Cr23C6 and so on. The average microhardness of the coating after application of ultrasonic vibration was 937HV, which was 13% higher than that of the coating not treated by ultrasonic vibration. The coefficient of friction was 0.43, which was reduced by about 26% and the wear resistance was improved by 44%. Laser cladding assisted by air-load ultrasonic vibration can significantly improve the quality of the coatings, make the microstructure more compact, and increase the hardness and wear resistance.