Molecular dynamics simulation of irradiation damage in V and TiVTa multi-principal element alloy

High entropy alloys with unique mechanical properties and irradiation resistance exhibit promising potentials as structural materials for advanced nuclear facilities. However, the formation behavior of irradiation defects in HEAs is still lacking of understanding. In this study, molecular dynamics simulations were employed to investigate the cascade collision of energetic ion in TiVTa and V, in order to compare the difference of their irradiation response. The results indicate that there is no significant difference in the initial stage of irradiation between these two materials, but as the irradiation damage accumulated, the residual defects in V is much more than in TiVTa, indicating that the recombination and annihilation rate of point defect in TiVTa is faster than in V. Mean square displacement calculations were also carried out to prove that self-interstitial atoms and vacancies have similar migration rate in TiVTa, therefore the self-interstitial atoms and vacancies produced in cascade collisions are more susceptible to combine and annihilate. These results will be helpful to unveil the mechanism of the irradiation response of HEAs.