Synthesis and characterization of FeCoNiCrCu high-entropy alloy coating by laser cladding

The influences of Si (1.2 mol.%), Mn (1.2 mol.%) and Mo (2.8 mol.%) additions on the microstructure, properties and coating quality of laser cladded FeCoNiCrCu high-entropy alloy coating have been investigated. The multi-component alloy coating is found to be a simple face-centered cubic (FCC) solid solution with less component segregation and high corrosion resistance, microhardness and softening resistance properties. For the coating without Si, Mn and Mo additions, the microstructure is mainly composed of columnar and equiaxed grains with uniformly distributed alloying elements. The microhardness reaches 375 HV0.5, which is about 50% higher than that of the same alloy prepared by arc melting technique. But the coating quality is very poor. While for the coating with Si, Mn and Mo additions, the coating quality is greatly improved, the microhardness increases to 450 HV0.5, but the microstructure transforms to dendrite due to a slightly increase in component segregation.