Atomistic simulations were made of the interaction between edge dislocations and self-interstitial atoms or vacancies in body-centered cubic material. The calculations were carried out using molecular dynamics and an energy minimization scheme which was based upon the quasi-Newton approach, plus the Finnis-Sinclair interatomic potential. A large anisotropy in the strain field of self-interstitials was observed, and this caused a strong interaction with edge dislocations; even when the defect was located on the dislocation glide-plane. The relaxation volume for vacancies was smaller and much more isotropic. This resulted in a far weaker interaction with the dislocation. A temperature-dependent capture-radius for vacancies and self-interstitials was deduced from the results. The difference between the capture radii of vacancies and self-interstitials was used to define the sink strength of the dislocation. Large deviations were observed from the predictions which were based upon treating point defects as isotropic dilatational centers. The capture radius of edge dislocations in body-centered cubic Fe was observed to be small and was of the order of 1 to 3nm for self-interstitials.

The Interaction between Point Defects and Edge Dislocations in BCC Iron. V.Shastry, T.Diaz de la Rubia: Journal of Engineering Materials and Technology, 1999, 121[2], 126-8