Clusters of self-interstitial atoms were formed in metals by high-energy displacement cascades, often in the form of small dislocation loops with a perfect Burgers vector, b. Atomic-scale computer simulation was used here to investigate their reaction with an edge dislocation gliding in α-Fe under stress for the situation where b was inclined to the dislocation slip plane. The b of small loops (37 self-interstitial atoms here) changed spontaneously and the interstitials were absorbed as a pair of super-jogs. The line glides forward at a critical stress when one or more vacancies were created and the jogs adopted a glissile form. A large loop (331 self-interstitial atoms here) reacted spontaneously with the dislocation to form a segment with b = <100>, which was sessile on the dislocation slip plane, and as applied stress increased the dislocation side arms were pulled into screw orientation. At low temperatures (100K), the <100> segment remained sessile and the dislocation eventually broke free when the screw dipole arms cross-slipped and annihilated. At 300K and above, the segment could glide across the loop and transform it into a pair of super-jogs, which became glissile at the critical stress. Small loops were weaker obstacles than voids with a similar number of vacancies, large loops were stronger. Irrespective of size, the interaction processes leading to super-jogs were efficient for absorption of self-interstitial atoms clusters from slip bands, an effect observed in flow localization.

Computer Simulation of Reactions between an Edge Dislocation and Glissile Self-Interstitial Clusters in Iron. D.J.Bacon, Y.N.Osetsky, Z.Rong: Philosophical Magazine, 2006, 86[25-26], 3921-36