Effect of nano-WC on wear and impact resistance of Ni-based multi-layer coating by laser cladding

The WC/Ni coatings were prepared by the laser cladding of Ni-based powders containing nano-WC particles with different contents. The effect of nano-WC particles on the wear resistance and impact resistance of Ni-based coatings were studied. The SEM and XRD were used to analyze the microstructure of the composite coating. The wear tester and charpy impact tester were used to test the wear resistance and impact resistance of the composite coatings. The microstructure of the coating is refined by nano-WC. The wear rate of the nano-WC coating was 53.43% lower than that of the Ni45 coating. The impact toughness of the coating was 13.37% higher than that of Ni45 coating. The nano-WC hinders the crack propagation in the grain boundary and eutectic region. Thus, the nano-WC can increase the impact energy required for coating fracture and significantly improve the impact toughness of the coating. Nano-WC can reduce the uneven slip of dislocations and alleviate the accumulation of dislocations by the analysis of the finite element. Nano-WC can effectively disperse the stress concentration formed in the impact process of the coating. Nano-WC can significantly improve the impact resistance of the composite coating. The results show that nano-WC can improve the wear resistance and impact resistance simultaneously.