Design and microstructure characterization of FeCoNiAlCu high-entropy alloy coating by plasma cladding: In comparison with thermodynamic calculation

Plasma cladding is an effect method to prepare a large-area coating as well as HEA coatings. In this work, the relatively simple microstructure of FeCoNiAlCu high-entropy alloy coating was successfully prepared by plasma cladding. The microstructure characterization and thermodynamic calculation were studied in detail. The synthesized FeCoNiAlCu high-entropy alloy coating is composed of an FCC1 phase enriched with Fe and Cu, an FCC2 phase enriched with Cu and a BCC phase enriched with Fe. The lattice parameter of FCC1, FCC2 and BCC phases are 3.664 angstrom, 3.634 angstrom and 2.872 angstrom, respectively. The thermodynamic calculation is successful to a certain extent,, agreeing with the experimental characterization well in terms of phase composition and the major en riched element of phases. However, establishing a developed database of CALPHAD approach is necessary to guide the design of high-entropy alloys and predict the phase composition and properties.