采用激光熔覆技术在45#钢表面制备NiAlBSi高温合金涂层。利用X射线衍射仪、扫描电镜、电子探针、显微硬度计、摩擦磨损试验机和热重分析仪，对不同激光扫描速度下合金涂层的相组成、微观组织、成分、显微硬度、耐磨性和高温抗氧化性进行了分析。研究结果表明，不同激光扫描速度下合金涂层皆是由树枝状NiAl金属间化合物构成。随着扫描速度的增加，由于树枝晶逐渐细化，合金涂层的硬度增加，但耐磨性能和抗高温氧化性则呈现出先增后降的变化趋势，在激光扫描速度为4 mm/s时，合金涂层具有最好的耐磨性能和抗高温氧化性能。

NiAlBSi high-temperature alloy coatings are prepared by laser cladding on the 45# medium steel. The microstructures and properties of the NiAlBSi alloy coatings obtained at different scanning velocities are investigated by means of X-ray diffraction, scanning electron microscopy, electron probe microanalyzer, Vickers hardness tester, friction wear testing machine, and thermal analyzer. The results show that all coatings consist of Ni-Al dendrites. With the increase of scanning velocity, the hardness values of the coatings increase gradually due to the refinement of dendrites, while the wear resistance and the high temperature oxidation resistance present the trend of first increasing then decreasing, and the highest values are obtained at the scanning velocity of 4 mm/s.