Effects of void and inclusion sizes on mechanical response and failure mechanism of AlCrCuFeNi2 high-entropy alloy

Abstract

The effects of various void sizes, inclusion sizes, and strain rates on the mechanical response, deformation behavior, and failure mechanism of AlCrCuFeNi2 high-entropy alloy samples with a pre-void/inclusion under the tension are investigated via the molecular dynamics. The results reveal that there exists a critical value of mechanical parameters such as the tensile strength and Young’s modulus in the tension of sample with an inclusion size of 15 Å, where the mechanistic parameters are changed. Meanwhile, the mechanical parameters decrease under increasing the void size and reducing the strain rate. The deformation behavior discloses that the void and inclusion are the principal cause of initial strain, and the shear bands are propagated inside the workpiece along the direction of an angle of 45° related to the tensile axis. The transformation from the FCC phase to other structures such as HCP and amorphous has occurred during deformation. Also, the HCP phase of inclusion shows relatively unstable, which is demonstrated by a rapid phase transformation of inclusion under a small strain. Finally, the dislocation evolution mechanism exhibits that it begins to nucleate around the void and inclusion, and the dislocations are then moved to free surfaces with increased strain.