Hardening due to copper precipitates in α-iron studied by atomic-scale modelling

We present results of a large-scale atomic-level study of dislocation-precipitate interaction. We have considered a (1)/(2) <1 1 1> edge dislocation gliding in alpha-iron containing coherent copper precipitates of size from 0.7 to 6 nm over a temperature range from 0 to 450 K. The results demonstrate that some features are qualitatively consistent with earlier theoretical conclusions, e.g. the critical resolved shear stress (CRSS) is proportional to L-1 and In(D), where L and D are precipitate spacing and diameter. Other features, which are intrinsic to the atomic-level nature of the dislocation-precipitate interaction, include strong dependence of the CRSS on temperature, dislocation climb and precipitate phase transformation. (C) 2004 Elsevier B.V. All rights reserved.