Results were reported of atomic-scale modelling to compare edge dislocation-void interaction in face-centered cubic copper and body-centered cubic iron. Voids of up to 6 nm diameter in iron and 8 nm diameter in copper were studied over the temperature range 0 to 600K at different applied strain rates. Voids in iron were strong obstacles, for the dislocation has to adopt a dipole-like configuration at the void before breaking away. The dipole unzips at the critical stress when the dislocation was able to climb by absorbing vacancies and leave the void surface. Dislocation dissociation into Shockley partials in copper prevents dislocation climb and affects the strength of small and large voids differently. Small voids were much weaker obstacles than those in iron because the partials break from a void individually. Large voids were at least as strong as those in iron, but the controlling mechanism depends on temperature.

Atomic-Scale Mechanisms of Void Hardening in BCC and FCC Metals. Y.N.Osetsky, D.J.Bacon: Philosophical Magazine, 2010, 90[7-8], 945-61