Abstract:In order to improve the surface wear resistance of metal parts, this study quantitatively analyzed the effect of ceramic particle content on the microstructure evolution and mechanical properties enhancement mechanism of high-entropy alloy gradient coating, and prepared dense and uniform high-entropy alloy gradient composite coating with different WC content on 45# steel substrate by laser cladding technology. The results show that with the increase of WC content, the grain size of the coating decreases from 20.16μm to 7.71μm, and the grain shape changes from cellular to dendrite and equiaxed. In addition, the microhardness of the gradient composite coating is significantly increased, which is 3 times that of the substrate, and 1.4 times higher than that of the high-entropy coating without adding WC. The coating mainly consists of body-centered cubic phase and metal carbide, and the corresponding diffraction peak intensity increases gradually with the increase of WC content. The wear performance test results show that the coating exhibits the best wear resistance when the WC content is 20 %, and the friction coefficient and wear amount are 0.4680 and 0.16 mg, respectively, which are lower than the WC40 coating with the highest average hardness, indicating that maintaining appropriate toughness while improving the hardness of the coating is the key to achieve the optimization of the coating performance. This study provides a certain reference value for the study of the optimization of high entropy alloy coatings prepared by laser cladding.