Effect of WC Content on Microstructure and Properties of CoCrFeNi HEA Composite Coating on 316L Surface via Laser Cladding.

Laser cladding technology is used to fabricate CoCrFeNi HEA/WC composite coatings with different mass fractions of WC on the surface of 316L stainless steel. The microstructures of HEA/WC composite coatings were analyzed by combining multiple characterization techniques. The results show that the HEA/WC composite coatings have good surface formation without pores and hot cracks, and the metallurgical bonding is well formed between the coating and the 316L SS substrate. Under the action of a laser beam and molten pool, WC particles partially or slightly melt and diffuse to the matrix, which hinders the orderly growth of grains and forms multiple strengthening. The phase structure of the HEA/WC composite coatings is composed of a main phase with FCC. The hardness and corrosion resistance of the HEA/WC composite coatings are clearly enhanced, and the HEA/WC composite coating with 5% WC has optimum properties.