Investigation on friction and wear performance of laser cladding Ni-based alloy coating on brake disc

Abstract Wear is the leading cause of brake disc failure. However, laser cladding technology provides a fast and environmentally friendly method to repair brake disc damage caused by wear. In this paper, Ni-based alloy powder was used to prepare the coating on the surface of the brake disc to improve its wear resistance, and the coating prepared by laser cladding was systematically studied. The main phases of the coating were γ-Ni and Ni3C, which were the main reasons for increasing the hardness and elastic modulus. The microstructure of the coating is compact. With the change of the solidification rate and temperature gradient, the microstructure changed from columnar to cellular, dendritic and equiaxed. By comparing the wear volume of the coating and substrate before and after wear, it was found that the coating has better wear resistance (about 1.5 times that of the substrate). Besides, the coating also has good oxidation resistance. The oxidation film formed during the wear process of the coating is beneficial to inhibit the regeneration of oxide. Therefore, according to the test results the laser cladding Ni-based coating is an effective means to improve the tribological properties of the brake disc.