Microstructure and mechanical property of as-cast, -homogenized, and -deformed AlxCoCrFeNi (0 ≤ x ≤ 2) high-entropy alloys

To have a further investigation of their physical properties such as electrical, magnetic, and thermal properties, the microstructure and mechanical property of AlxCoCrFeNi alloys have to have a detailed and systematic study. We present the effects of Al content on microstructure and mechanical property of as-cast, -homogenized, and -deformed AlxCoCrFeNi alloys in this study. It shows that single FCC and single BCC solutions, and duplex FCC–BCC are principal phases in these alloys. The x intervals for duplex FCC–BCC of different states of these alloys are investigated. The spinodal decomposition of less Al–Ni and more Al–Ni phases is the major reaction during homogenization of the alloys. The morphology of the less and more Al–Ni phases is also discussed. There is no stress-induced phase transformation during 50%-rolling deformation, and the main strengthening mechanism is work hardening. The hardening ability of FCC was about twice that of BCC in this alloy system.