The evolution of the microstructure of dilute Fe alloys under irradiation was modelled using a multiscale approach based on ab initio and atomistic kinetic Monte Carlo simulations. In these simulations, both self interstitials and vacancies, isolated or in clusters, were considered. Isochronal annealing after electron irradiation experiments were simulated in pure Fe, Fe–Cu and Fe–Mn dilute alloys, focusing on recovery stages I and II. The parameters regarding the self interstitial – solute atom interactions were based on ab initio predictions and some of these interactions were slightly adjusted, without modifying the interaction character, on isochronal annealing experimental data. The different recovery peaks were globally well reproduced. These simulations allow interpreting the different recovery peaks as well as the effect of varying solute concentration. For some peaks, these simulations have allowed to revisit and re-interpret the experimental data. In Fe–Cu, the trapping of self interstitials by Cu atoms allows experimental results to be reproduced, although no mixed dumb-bells were formed, contrary to the former interpretations. Whereas, in Fe–Mn, the favorable formation of mixed dumb-bell plays an important role in the Mn effect.

Isochronal Annealing of Electron-Irradiated Dilute Fe Alloys Modelled by an ab initio Based AKMC Method: Influence of Solute–Interstitial Cluster Properties. R.Ngayam-Happy, P.Olsson, C.S.Becquart, C.Domain: Journal of Nuclear Materials, 2010, 407[1], 16-28