Effect of pre-deformation and B2 morphology on the mechanical properties of Al0.5CoCrFeNi HEA

Al0.5CoCrFeNi is a promising alloy in the AlxCoCrFeNi series, since it contains a mixture of the ductile fcc phase (A1) and the hard and ordered bcc phase (B2). The combination of the two forms a "metallic composite" with mechanical properties that can be modified by different thermo-mechanical treatments. In this study, it was shown that deformation prior to heat treatment can alter the B2 phase morphology from "plate-like" to equiaxed morphology. The mechanical properties of Al0.5CoCrFeNi were determined by utilizing compression experiments in conjunction with non-linear finite element analysis. The results showed that in all cases, pre-heat treatment deformation led to a reduction in the effective yield stress. This behavior correlates with the changes in the B2 morphology resulting from the pre-heat treatment deformation. Moreover, the effective yield stress decreased with increasing heat treatment temperature for both pre-deformed and undeformed samples.