Microstructure, thermodynamics and compressive properties of Al0.5CoCrCuFeNi-X (X=V,Si,VSi) high-entropy alloys

The article investigated the effect of V and Si on the microstructure, thermodynamics and compressive properties of Al0.5CoCrCuFeNi high-entropy alloy (HEA). Four Al0.5CoCrCuFeNi-X(X = V, Si, VSi) HEAs were prepared by vacuum arc melting. With the addition of V and Si, the microstructure of the Al0.5CoCrCuFeNi HEA changes from FCC to FCC + BCC. The (Ω, δ)-values of the four HEAs meet the formation condition of solid solution. Their VEC-values in the range of [6.87–8] explain the reason for FCC and FCC + BCC formation in the four HEAs. The V and Si elements greatly improve the hardness of the three HEAs. The fracture mechanisms of X = V, Si, VSi HEAs are the composite fracture, quasi-cleavage fracture and purely brittle cleavage fracture, respectively.