Abstract:Six kinds of NiCrBSi coatings with different spray angles of 40°, 50°, 60°, 70°, 80° and 90° were prepared by HVOF technology. The microstructure, porosity, microhardness, and wear properties of the coatings at 25 ℃, 400 ℃ and 600 were studied. The results show that the microstructure of coatings prepared from different spraying angles id different. When the spraying angle are 40° and 50°, there are no unmelted/semi-melted particles in the coating. When the coating angle reaches 60° or above, there are unmelted/semi-melted particles in the coating, and the deposition efficiency is significantly improved. The microhardness of the coating reaches its maximum value of 837.2 HV0.1 at spray angles of 50° and 90°. The average friction coefficient of the same coating decreases with the increase of test temperature. At room temperature, the wear rate of the 50° spray coating is the lowest. When the wear test temperature rises to 400 ℃ and 600 ℃, the wear rate of the 90° spray coating is the lowest. The wear mechanism of the coating at temperatures of 25 ℃ and 400 ℃ is mainly manifested as fatigue wear, and at 600 ℃, the 90° spray coating exhibits abrasive wear characteristics. Compared with the coating prepared by the spraying angle of 40°, the unmelted/semi-melted particles in the coating prepared by the spraying angle of 90° play a "pinning effect", which helps to improve the wear resistance of the coating both at room temperature and high temperature environments.