Deformation Behavior of Single-Crystal Al0.3 CoCrFeNi Hea Alloy with Various Inclusion Materials During the Tensile Process

Abstract

This work employs molecular dynamics simulations to explore how different embedded inclusions (Al, Co, Cr, Fe, and Ni) affect the tensile response and deformation mechanisms of single-crystal Al0.3CoCrFeNi high-entropy alloys. The findings show that inclusion composition has a significant impact on mechanical performance. Among the investigated cases, the specimen containing a Cr inclusion exhibits the highest yield strength and superior resistance to plastic deformation, whereas the Al-inclusion sample shows the lowest mechanical performance. During loading, stress concentration develops around the inclusion-matrix interface, which serves as the primary site for shear-strain localization and dislocation nucleation. As deformation progresses, shear bands propagate diagonally across the specimen, forming approximately 45° to the loading direction. Structural analysis demonstrates that regions adjacent to the inclusions undergo significant atomic rearrangement, including the formation of HCP and amorphous phases from the initial FCC matrix. Furthermore, Cr- and Fe-based BCC inclusions as well as HCP Co inclusions experience partial transformation toward FCC-like configurations because of interfacial interactions with the surrounding alloy matrix. The evolution of dislocations indicates that inclusions act as preferential sources for defect generation, followed by extensive dislocation propagation toward free surfaces under increasing strain.