The preexisting edge dislocations as recombination center of point defects enhancing irradiation tolerance in CoCrCuFeNi high entropy alloy

Defect clusters including dislocations, grain boundaries, and precipitations can serve as sink sources for point defects during radiation damage. As a result, radiation tolerance can be tuned by engineering the defects in the structural materials, however, is a challenging topic due to the complexity. In this paper, the mechanism of interaction between the preexisting dislocation and the displacement cascade in CoCrCuFeNi high entropy alloy (HEA) is investigated using molecular dynamics simulations. The results show that the dislocation climbs, and promotes the diffusion of point defects generated by the cascade to the dislocation line. As a result, it increases the probability of defect annihilation and recombination and therefore strengthens radiation tolerance. The interaction of dislocations with void in CoCrCuFeNi and Ni shows that CoCrCuFeNi high entropy alloy has excellent resistance to irradiation hardening. Our atomic insights could be beneficial in the design of high-performance irradiation resistant high entropy alloys.