Microstructure and properties of argon arc cladded CoCr x FeMoNiAl high entropy alloy coatings on Q235 steel

Abstract In this paper, the CoFeMoNiAlCr x coatings with different chromium content (x = 0, 0.3, 0.6, 0.9 and 1.2) were prepared by argon arc cladding technology on Q235 steel. The microstructure and phases of the coatings were analyzed by OM, SEM, EDS and XRD. The hardness, wear resistance and corrosion resistance of the coatings were tested by microhardness tester, friction and wear tester and electrochemical workstation. The results show that the highest hardness is obtained in the CoFeMoNiAlCr x=0 high entropy alloy coatings, about 500 HV, which is about 3 times than the hardness of Q235 steel (the substrate). With the chromium content of the CoFeMoNiAlCr x coatings increasing, the wear resistance increases first, and then decreases. When the chromium content is 0.9, the wear resistance of the coating is the highest with the wear loss about 2.6 mg and the friction coefficient about 0.52. The corrosion resistance of the coatings decreases with a small amount of chromium addition. When the Cr content in the coating is close to the atomic ratio, the content of the body-centered cubic phase structure increases, and the face-centered cubic phase structure appears in the coating.