Taylor impact of high-entropy alloy Al0.1CoCrFeNi: Dynamic severe plastic deformation and bulk gradient structure

Abstract

Taylor impact experiments are conducted on a typical face-centered cubic single-phase high-entropy alloy (HEA) Al0.1CoCrFeNi, to investigate its dynamic severe plastic deformation and gradient structure. Parameters of the Johnson–Cook constitutive model are obtained, and finite element modeling based on this model is consistent with the experimental observations. A bulk gradient structure with deformation gradient is generated directly via the Taylor impact. The deformation mechanisms include the {111}〈112〉 deformation twins and kink bands with the 〈110〉 or 〈112〉 rotation axes, and vary considerably along the impact direction. Subsequent annealing at 800∘C and the impact-induced gradient in the degree of re-crystallization lead to a new bulk gradient structure with gradients in grain size and proportion of the non-recrystallized region, providing a novel approach to developing bulk gradient structured materials.