Effects of Cu/Si on the microstructure and tribological properties of FeCoCrNi high entropy alloy coating by laser cladding

High entropy alloy coatings show great potential for improving the wear resistance of the stainless-steel substrate. However, there are few comparative studies on the tribological properties of high entropy alloy coatings with different elements. In the present study, the FeCoCrNiCux and FeCoCrNiSix high entropy alloy coatings were designed and prepared by laser cladding. The microstructures of the high entropy coating were analyzed. The tribological properties of the high entropy alloy coatings sliding against Si3N4 balls at room temperature and 600 °C were investigated. The results show that after adding Cu/Si, the tribological properties of the coating change little at room temperature, but increased significantly at high temperature of 600 °C. The FeCoCrNiSi coating has the best tribological performance at 600 °C with an average friction coefficient and wear rate of 0.19 and 0.677 (×10−4 mm3/N·m), respectively. In general, the addition of Cu increases the thermal conduction ability of the coating, improves the toughness and the bonding strength of the coating; the addition of Si refines the grain size, increases the degree of work hardening and improves the wear resistance of the coating.