Microstructures and properties of AlCrFeNiMnx high-entropy alloy coatings fabricated by laser cladding on a copper substrate

In this study, AlCrFeNiMnx high-entropy alloy coatings (x = 0, 0.5, and 1) were successfully prepared on a copper substrate by laser cladding. The influence of Mn addition was investigated on the phase constituent, microstructure, and mechanical properties of the HEA coatings. Due to the high-entropy effect, the AlCrFeNiMnx HEA coatings comprised only simple BCC and FCC structure phases. Moreover, the addition of Mn elements inhibited the formation of FCC phases due to the variation of ΔGmix, ΔHmix, δ, ∆x and VEC value. The addition of Mn leads to solute effect, so the grains were significantly refined with an increase in Mn content. When the Mn content was 0.5, good comprehensive mechanical properties were obtained with an average Vickers hardness of 625 HV, average friction coefficient value of 0.42, and a mass loss of 1.02 mg.