FeCrNiMnAl high-entropy alloy coating by spray deposition and thermite reaction

High-entropy alloy (HEA) coatings demonstrate excellent corrosion resistance and wear resistance. However, their applications are limited owing to a complicated process and high costs. In the present work, an FeCrNiMnAl HEA coating was synthesised by spray deposition combining with thermite reaction using a mixture of Fe2O3, CrO3, MnO2, Ni, and Al powders as precursors. After spray deposition, the as-formed coating layer consisted of two body-centred cubic phases, and showed good metallurgical bonding with the substrate. The average microhardness value of the FeCrNiMnAl HEA coating reached 432.2 +/- 10.8 HV, which was higher than that of the substrate (259.5 +/- 8.4 HV). The coating also exhibited superior wear resistance and corrosion resistance compared with the substrate. This method has great potential for preparing HEA coatings.