目的 研究激光扫描速度对激光熔覆层组织与性能的影响。方法 采用通快TRUMPF Laser TruDisk 4002光纤激光器，在扫描速度分别为300、400、500 mm/min时，制备激光熔覆Ni基增强涂层，利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）、能谱分析仪（EDS）分析了熔覆层的微观组织和物相组成，利用显微硬度计及摩擦磨损试验机测试了熔覆层的显微硬度和耐磨损性能。结果 熔覆层主要由TiC、TiB2、Ti2Ni及γ-Ni等物相组成。随着扫描速度的增加，Ti811基材烧损程度逐渐减弱，熔覆层宽度W、高度H、基体熔深h及稀释率λ均逐渐减小。当扫描速度为500 mm/min时，熔覆层组织明显细化，平均显微硬度可达920HV0.5，超过基体硬度的2倍。扫描速度为300、400、500 mm/min时，熔覆层的平均摩擦系数分别为0.45、0.40、0.38，平均磨损量为2.1、1.7、1.4 mg。结论 采用激光熔覆技术能够在Ti811表面成功制备Ni基复合增强涂层。选择适当的激光扫描速度可以改善熔覆层显微组织，当激光扫描速度为500 mm/min时，熔覆层晶粒细小，组织分布致密均匀，显微硬度与耐磨损性能显著提高。

The work aims to study the effect of laser scanning speed on the microstructures and properties of laser cladding layers. The laser cladding Ni-based reinforced coatings were prepared by a TRUMPF Laser TruDisk 4002 fiber laser at the scanning speed of 300, 400 and 500 mm/min, respectively. The microstructure and phase composition of the laser cladding layers were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) and the microhardness and wear resistance of the cladding layers were tested by microhardness tester and friction wear tester. The microstructure of cladding layer was mainly composed of TiC, TiB2, Ti2Ni and γ-Ni. With the increase of scanning speed, the burning loss degree of Ti811 substrate decreased and the width W, height H, penetration of the substrate h and dilution rate λ also decreased gradually. When the scanning speed was 500 mm/min, the microstructure of the cladding layer was obviously refined and the average microhardness was up to 920HV0.5 which was 2 times of the microhardness of the substrate. When the scanning speed was 300, 400 and 500 mm/min, the average friction coefficient of the cladding layers was 0.45, 0.40 and 0.38 and the average wear mass loss was 2.1 mg, 1.7 mg and 1.4 mg. The Ni-based composite reinforced coatings can be successfully prepared by laser cladding technology on Ti811 alloy surface. The microstructure of cladding layer can be improved by selecting appropriate laser scanning speed. When the laser scanning speed is 500 mm/min, the grain size of the cladding layer is fine, the distribution of microstructure is dense and uniform and the microhardness and wear resistance are significantly increased.