Influence of rhenium-decorated dislocation loops on edge dislocation gliding in tungsten

Rhenium (Re), as a typical alloying and transmutation element in tungsten (W), can significantly enhance the irradiation hardening, but its underlying mechanism remains to be elucidated due to the complicated Re-defect interactions. Here, using molecular dynamics simulations, we demonstrate that Re aggregation on dislocation loops have effect on the interaction with edge dislocations. Especially for the "parallel loop" case, Re-decorated loops become the strong obstacles for edge dislocation gliding from weak ones of pure loops or Re-rich clusters. Such synergetic pinning effect is dependent on the Re concentration and it modifies the complexes turning to strong obstacles once Re exceeds a certain critical concentration. This is originated from the coupling of Re with dislocation loops in W, which impedes the glide of edge dislocations and contributes greatly to the irradiation hardening. Our results give a new insight to rationalize and account for the irradiation hardening in W-Re systems.