Irradiation hardening by interstitial loops: atomistic study and micromechanical model

We present molecular dynamics simulations of the interactions between gliss ile interstitial loops and an edge dislocation in a fee nickel crystal. Thi s study shows atomic-scale reactions leading to a pinning of the dislocatio n by the loops which are dragged along when the dislocation unpinns. This a tomic-scale information is incorporated in a micromechanical model. Predict ions of the model at the micron scale are compared to the initial hardening and subsequent softening of irradiated specimens observed experimentally i n traction tests. (C) 2001 Elsevier Science B.V. All rights reserved.