Abstract:In order to improve the wear resistance of aerospace aluminum alloy, especially to ensure the normal use of aluminum alloy under increasing temperature, this study designs a three-dimensional diffusion layer to enhance the bonding between coating and the substrate. Through-thickness composite coating was prepared on the surface of aluminum alloy by means of mechanical ball milling, laser texture microporous and electrodeposition, the mechanical and tribological properties of the composite coating were tested and analyzed. The results show that the electrodeposited Ni coating completely covers the texture surface of mechanical milling coating, and the microhardness of mechanical milling coating and electrodeposition coating is about 285 and 165 HV respectively, after heat treatment. Moreover,a three-dimensional diffusion layer is formed at the interface of aluminum alloy substrate, mechanical milling coating and electrodeposition coating. The tribological properties of aluminum alloy perform normal at room temperature, but show signs of failure at 300℃.For four composite coatings, the friction coefficient of N150 composite coating is the lowest at room temperature, which is about 0.7. The friction coefficient of N100, N150 and N200 composite coatings is about 0.5 at 300℃. The wear rates of the four samples are in the range of (0.9~1.6)×10-3 mm3/(N·m) at room temperature and 300℃ with N100 and N150 composite coatings performing slightly better. The prepared composite coating can effectively protect the aluminum alloy substrate at room temperature and 300℃,and extend the applicable temperature of aluminum alloy.