Effects of stress states and strain rates on mechanical behavior and texture evolution of the CoCrFeNi high-entropy alloy: Experiment and simulation

Abstract

The effects of stress states and strain rates on mechanical behaviors and texture characteristics of the CoCrFeNi high-entropy alloy (HEA) were investigated via shear-tension specimens and Split-Hopkinson Tensile Bar (SHTB). The results revealed that the stress states and strain rates have an obvious influence on the mechanical properties and texture evolution. The volume fractions of textures S {123}<634> and Brass {110}<112> both increase with the decline of shear stress component under different stain rates, but their volume fractions are larger at high strain rates. The strength and elongation of the CoCrFeNi HEA are simultaneously increased at high strain rates and complex stress states. In addition, a crystal plasticity finite element model (CPFEM) with a damage factor was established to simulate the stress distribution and damage evolution at quasi-static condition. The results showed that the CPFEM can exactly predict the texture and damage characteristic of the CoCrFeNi HEA under different stress states at quasi-static deformation.