Effect of Cu Content on Microstructure and Properties of Iron-based Medium Entropy Alloy Coating.

The medium entropy alloy coatings (Fe_63.3 Mn₁₄ Si_9.1 Cr_9.8 C_3.8)_{100- x} Cu_x (x = 0, 1 at. %, 3 at. %, 5 at. %,7at. %) were prepared by laser cladding method. The effects of Cu content on phase, microstructure, microhardness and corrosion resistance of the coatings were investigated. The results show that with the increase of Cu element content, the coatings all possess a single FCC phase with a typical dendritic structure. The microhardness decreases with the increase of Cu content, but it is higher than that of 304 stainless steel. In 3. 5% NaCl solution, (Fe_63.3 Mn₁₄ Si_9.1 Cr_9.8 C_3.8)₉₉ Cu₁ medium entropy alloy coating exhibits the highest corrosion potential, which moves 29 mV in the positive direction compared with 304 substrate, and the lowest corrosion current density of 4.977 x 10^-6 A/cm², the coating surface corrosion mainly occurs slight grain boundary corrosion. (Fe_63.3 Mn₁₄ Si_9.1 Cr_9.8 C_3.8)_100-x Cu_x alloy coating with low Cu content has high hardness and corrosion resistance, and optimal potential value. [ABSTRACT FROM AUTHOR]