Microstructure and Properties of an FeCoCrAlCu HEA Coating Synthesized via the Induction Remelting Method

Abstract

An FeCoCrAlCu HEA coating was prepared on the surface of 45# steel by cold-spray-assisted induction remelting. The results showed that the FeCoCrAlCu HEA coating was composed of BCC and FCC phases. The BCC phase possessed an amplitude-modulated structure consisting of a B1-disordered phase (FeCr) and a B2-ordered phase (AlCo), as well as a nanoscale BCC phase precipitated near grain boundaries. The FCC phase was composed of a solid solution of the Al–Cu matrix and manifested characteristics of a typical twin structure. In addition, the hardness of the FeCoCrAlCu HEA coating was 528.2 HV. The friction coefficient of the FeCoCrAlCu HEA-/Al2O3 pair was 0.379, and the wear rate was 3.96 × 10−5 mm3/(N × m). In 3.5 wt.%NaCl and 5.0 wt.%H2SO4 corrosive media, the FeCoCrAlCu HEA coating had a more positive self-corrosion potential (Ecorr) and a lower corrosion current density (Icorr) than the substrate.