Nucleation of interstitial dislocation loops in metals under electron irradiation

Abstract

A hybrid model of the dislocation loop nucleation in metals during electron irradiation is pro posed. The model is based on the kinetic diffusion mechanism of formation and growth of three dimensional interstitial atomic clusters and the thermodynamic mechanism of intermittent transformation of these clus ters in dislocation loops. The existence of critical input rate G C of freely migrating point defects is established. When G < G C , loops of minimum size consisting of four atoms are formed at the stage of nucleation. With increasing G at G > G C , the number of interstitial atoms increases (n 0 ≥ 4). By analyzing experimental data for the electron irradiated aluminum, it is shown that, using the formulas of the proposed model, one can cal culate all parameters of nucleation of interstitial dislocation loops at a given magnitude of the input rate of freely migrating defects without performing experimental studies.