Effect of WC Addition Amount on Microstructure and Corrosion Resistance of Mo₂FeB₂ Cermet Coating

Mo₂FeB₂ cermet coatings modified with different mass fractions (0, 10%, 15%, 20%, 25%) of WC were prepared on Q235 steel by plasma spraying. The effect of WC addition amount on the phase composition, microstructure and corrosion resistance of the coatings was studied. The results show that the Mo₂FeB₂ cermet coatings modified with WC were mainly composed of Mo₂FeB₂, WC, W₂C, Fe and iron oxides phases. When the mass fraction of WC increased from 0 to 15%, the amount of Mo₂FeB₂ and WC double hard phases of cermet coating increased, and the size of those decreased and the distribution tended to be uniform. When the WC mass fraction was more than 15%, the double hard phases gathered, the porosity increased, and the compactness of the coating decreased. When the WC mass fraction was 15%, the coating structure was most uniform and compact, and the corrosion resistance was the best.