The effects of He-vacancy (He-V) clusters on the mobility of an a/2<111>{110} edge dislocation in α-Fe were investigated by atomic simulation with empirical potentials at 0K. A number of small HenVm (n/m 0–4) clusters initially placed at the same position on the slip plane were comparatively studied. The results show that the interaction of He-V clusters with edge dislocations depends on not only the helium-to-vacancy (He/V) ratio, but also the cluster size. The small He-V clusters with low He/V ratios have a small effect on the dislocation mobility, but the larger clusters with higher He/V ratios significantly increase the critical resolved shear stress for dislocation glide. One of interesting results was that the He-V clusters almost stay at their original positions, and do not move along with the dislocation.

Dynamic Interactions of Helium-Vacancy Clusters with Edge Dislocations in α-Fe. L.Yang, X.T.Zu, F.Gao, S.M.Peng, H.L.Heinisch, X.G.Long, R.J.Kurtz: Physica B, 2010, 405[7], 1754-8