Molecular dynamics simulations of interaction of cascade damage with self-interstitial atom-loaded grain boundaries in tungsten

In this study, we conducted systematic molecular dynamics simulations to investigate the radiation resistance of grain boundaries (GBs) in tungsten with/without self-interstitial atoms (SIAs) loaded on them. The simulation results show that the presence of SIAs can extend the width of the Σ3<110>{112} twin GB compared to the SIA-free GB. When cascade damage occurs near Σ3, the presence of SIAs at Σ3 enhances radiation resistance. Specifically, it inhibits producing residual defects, particularly vacancies and prevents their aggregating into clusters. The radiation-resistant performance is most excellent when the SIA concentration at Σ3 is approximately 5%. The influence of temperature and primary knock-on atom energy on radiation damage is also discussed. However, SIA-loaded high angle GBs and low angle GBs do not significantly enhance their radiation-resistant performance compared to their SIA-free counterparts. This study provides valuable insights into the radiation damage behaviors near GBs and contributes to understanding their radiation-resistant mechanisms.