Atomic-level simulations were used to investigate the interaction of an edge dislocation with <100> interstitial dislocation loops in α-iron at 300K. Dislocation reactions were studied systematically for different loop positions and Burgers vector orientations, and results were compared for two different interatomic potentials. Reactions were wide-ranging and complex, but could be described in terms of conventional dislocation reactions in which Burgers vector was conserved. The fraction of interstitials left behind after dislocation breakaway varies from 25 to 100%. The nature of the reactions requiring high applied stress for breakaway was identified. The obstacle strengths of <100> loops, ½<111> loops and voids containing the same number (169) of point defects were compared. <100> loops with Burgers vector parallel to the dislocation glide plane were slightly stronger than <100> and ½<111> loops with inclined Burgers vector: voids were about 30% weaker than the stronger loops. However, small voids were stronger than small ½<111> loops. The complexity of some reactions and the variety of obstacle strengths poses a challenge for the development of continuum models of dislocation behaviour in irradiated iron.

Simulation of the Interaction between an Edge Dislocation and a <100> Interstitial Dislocation Loop in α-Iron. D.Terentyev, P.Grammatikopoulos, D.J.Bacon, Y.N.Osetsky: Acta Materialia, 2008, 56[18], 5034-46