The existence of WC hard particles is one of the reasons for the high hardness and excellent wear resistance of the nickel-based tungsten carbide coating. However, the uneven distribution of its unmelted particles in the nickel-based tungsten carbide coating and the sinking phenomenon will cause microcracks and pores in the cladding layer during the solidification process of the WC boundary, resulting in the uneven distribution of the coating hardness and surface wear rate, as well as the increase of the residual stress and crack tendency of the coating.

In order to improve the above problems, in addition to the methods of preheating the substrate, optimizing the laser cladding process parameters, controlling the mass fraction of WC, and adding nanometer WC particles, many researchers found that it can also be achieved on this basis by functional gradient coating or adding trace alloying elements and rare earth elements to the nickel-based tungsten carbide matrix.