Microstructure and Properties of FeCrMnxAlCu High-Entropy Alloys and Coatings

FeCrMnxAlCu (x = 0.5, 1, 1.5, and 2) high-entropy alloys (HEA) and coatings were prepared through vacuum arc melting and cold spray-assisted induction remelting processes. This study investigated the effect of different Mn contents on the microstructure and wear resistance of HEAs and coatings. The results showed that the high-entropy FeCrMnxAlCu alloy prepared through vacuum arc melting and cold spray-assisted induction remelting processes comprised simple body-centered cubic and face-centered cubic phases with dendritic + interdendrite structures. The coating of the prepared alloys exhibited superior performance compared with the cast alloy. In addition, the hardness of the FeCrMnxAlCu HEA coatings synthesized through induction remelting was 1.4 times higher than that of the cast FeCrMnxAlCu HEA. Moreover, the wear rate of induction-remelted produced HEA coating was reduced by 24% compared with that of vacuum arc-melted produced HEA. The hardness of the induction-remelted produced FeCrMnxAlCu HEA coating initially increased and then decreased with increasing Mn contents. At x = 1, the hardness of FeCrMnAlCu HEA coating reached a maximum value of 586 HV, with a wear rate of 2.95 × 10−5 mm3/(N·m). The main wear mechanisms observed in the FeCrMnxAlCu HEA coatings were adhesive, abrasive, and oxidative.