Effect of WC content on microstructures and mechanical properties of FeCoCrNi high-entropy alloy/WC composite coatings by plasma cladding

Abstract

FeCoCrNi high-entropy alloy/WC composite coatings were fabricated via plasma cladding on steels adding different mass fraction of WC. Effects of WC content on the microstructure and mechanical properties of the coatings were studied. The results showed that WC content significantly affected microstructure and the wear resistance of the coatings. With the increase of WC content, the microstructures of the coatings became complex. When WC content was more than 60%, the coatings consisted of WC, FCC phase of HEA matrix as metal bond, Fe3W3C carbide phase and Cr-rich secondary solid solution phase. The Fe3W3C carbides improved the hardness and wear resistance of the coating. When WC content was at a high proportion of 60%, the HEA/WC coating had the best wear resistance with the minimum volume wear rate of 3.27 × 10−7 mm3/N·m and the high hardness of 59.6 HRC, which was better than commercial Ni60/WC coating with the same WC content.