Effect of chemical short-range order on primary radiation damage in TiVTaNb high-entropy alloys

Molecular dynamics simulations were carried out to study the effect of chemical short-range order (CSRO) on the primary radiation damage in TiVTaNb high-entropy alloys (HEAs). We have performed displacement cascade simulations to explore the CSRO effect on the generation and evolution behaviors of irradiation defects. The results demonstrate that CSRO can suppress the formation of Frenkel pairs in TiVTaNb HEAs, with the suppression effect becoming more pronounced as the degree of CSRO increases. CSRO can change the types of interstitial defects generated during cascade collisions. Specifically, as the degree of CSRO increases, the proportion of Ti-related interstitials shows a marked enhancement, primarily evidenced by a significant rise in Ti–Ti dumbbells accompanied by a corresponding decrease in Ti–V dumbbells. CSRO exhibits negligible influence on defect clustering and the nucleation and evolution of dislocation loops. Regardless of CSRO conditions, TiVTaNb HEAs preserve exceptional radiation tolerance throughout the cascade damage process, suggesting that the intrinsic properties of this multi-principal element system dominate its radiation response. These findings provide fundamental insights into the CSRO effect on defect formation and evolution behaviors in HEAs, which may provide new design strategies for high-entropy alloys.