Microstructure evolution and frictional wear behavior of laser cladding FeCrCoNiMo0.5Wx high-entropy alloy coatings

FeCrCoNiMo 0.5 W x (x = 0,0.25,0.5,0.75,1.0) HEA coatings were prepared on Q235 surfaces by laser cladding technique, the microstructure and phase composition of the coatings were analyzed to investigate the corrosion resistance , frictional wear properties, and wear mechanisms. The results showed that the increase of W caused the coating to produce μ phase, and the FeCrCoNiMo 0.5 W x HEA coating consisted of FCC solid solution and intermetallic compound σ phase and μ phase. The microstructure of the coating possesses a typical dendrite region (DR)-inter-dendrite (ID) structure, and the grain size is significantly refined after the addition of W. With the increase of W content, the microhardness and wear resistance of the coating gradually increased, among which the microhardness of W 1.0 coating was the highest and the wear resistance was the best. The wear mechanism of the coating is mainly oxidation wear, adhesive wear and slight abrasive wear . The addition of a small amount of W promotes the formation of a more stable passivation film. Further increasing the content of W, the phase content of the coating increases, resulting in a highly inhomogeneous passivation film, which reduces the corrosion resistance of the coating. The W 0.25 coating has the best overall corrosion resistance.