The effect of grain boundary on irradiation resistance of CoCrCuFeNi high entropy alloy

Defect traps have been well known to influence the irradiation resistance of traditional structural materials, but to what extent is not fully clear for high entropy alloys. Herein, the effect of grain boundary on irradiation resistance of CoCrCuFeNi is investigated through defects capture, strength variation, and void annihilation via molecular dynamics simulations and compared to that of pure Ni, taking ∑5(2 1 0) as a representative grain boundary. The grain boundaries in both CoCrCuFeNi and Ni are effective in capturing point defects. The number of captured defects is related to the distance between primary knock-on atoms and grain boundary. The change in tensile stress of CoCrCuFeNi after irradiation is smaller than that of Ni. The grain boundary of CoCrCuFeNi can annihilate voids at room temperature. However, that of Ni is hindered in the migration process and cannot annihilate voids completely. Our results provide atomistic insights into the mechanism of radiation resistance via grain boundaries as recombination centers.