Effect of Nb, Zr and NbZr on Microstructure and Compressive Properties of Al0.5CoCrCuFeNi-X(X = Nb, Zr, NbZr) High-Entropy Alloys

In the present study, the effect of Nb and Zr on the microstructure, thermodynamics and compressive properties of Al_0.5CoCrCuFeNi high-entropy alloy (HEA) was investigated. Four Al_0.5CoCrCuFeNi-X(X = Nb, Zr, NbZr) HEAs were prepared by vacuum arc melting. The Al_0.5CoCrCuFeNi is composed of single FCC solid solution, while the X = Nb, Zr and NbZr HEAs are composed of BCC and FCC solid solutions. The Nb and Zr elements greatly improve the microhardness of the X = Nb, Zr and NbZr HEAs by 127%, 58.6% and 180.2%, respectively. The fracture mechanisms of X = Nb, Zr and NbZr HEAs are purely brittle cleavage fracture. The X = Nb HEA has excellent comprehensive mechanical properties with high compressive strength, ultimate strain and microhardness.