Wear and corrosion of CoCrFeNiMnTi x high entropy alloy coatings by laser cladding

CoCrFeNiMnTi x ( x = 0.5, 1.0, 1.5, 2.0 in atomic ratio) high entropy alloy (HEA) coatings were prepared on 304 stainless steel by laser cladding. Experimental results showed that the CoCrFeNiMnTi x HEAs constituent phase evolved from a single FCC phase for the HEA to FCC + BCC + Intermetallic + Laves phases with the addition of Ti element. The CoCrFeNiMnTi x coatings exhibited an increasing microhardness from 412.42 HV to 573.97 HV. Accompanying the increase in microhardness, the wear resistance was proportional to the hardness of the coating, which met Archard's relationship. In addition, the corrosion resistance of the CoCrFeNiMnTi x coatings displayed an increased tendency firstly and then decreased with the addition of Ti element. And, the HEA coating with x = 1.0 possessed the highest corrosion resistance as indicated by the lower corrosion current density, high charge transfer resistance and high pitting potential.