Preparation and properties of laser cladding FeCoNiSi1.5Crx high entropy alloy coating

To advance the development of high-performance surface protective coatings, this study employed laser cladding technology to fabricate FeCoNiSi1.5Crx (x = 1, 1.2, and 1.5) high-entropy alloy coatings on 304 stainless steel substrates. The effects of different chromium concentrations on the microstructure, wear resistance, and corrosion resistance of the coatings were systematically investigated. Experimental results demonstrate that increasing the Cr content enhances the quantity of hard phases in the coating, leading to a significant improvement in microhardness. When x = 1.5, the wear volume of the coating was reduced by 80% compared to x = 1. Furthermore, in both tested corrosive media, the 304 stainless steel substrate exhibited inferior corrosion resistance to the high-entropy alloy coatings. In a 3.5 wt. % NaCl solution, an increase in the Cr content lowered the corrosion potential, reduced the impedance radius, and resulted in an overall decline in corrosion resistance. In a 0.5 mol/l H2SO4 solution, the corrosion resistance of the coating initially improved with increasing the Cr content, reaching an optimum at x = 1.2; however, further increasing the Cr content led to a deterioration in corrosion performance.