It was recalled that high-energy particle irradiation of low stacking-fault energy face-centered cubic metals produced a significant degradation of the mechanical properties; as shown by tensile tests which were performed at, or near to, room temperature. Post-irradiation examination revealed that some 90% of the radiation-induced defects in Cu were stacking-fault tetrahedra. Radiation damage was an inherently multi-scale phenomenon which involved processes that spanned a wide range of length and time scales. A multi-scale modelling method was used here to study the formation and evolution of defect microstructures, and the corresponding mechanical property changes under irradiation. Molecular dynamics simulations were used at the atomic scale to study the evolution of high-energy displacement cascades, the formation of stacking-fault tetrahedra from the vacancy-rich regions of displacement cascades and the interaction of stacking-fault tetrahedra with moving dislocations. Defect accumulation under irradiation was modelled over diffusional length and time scales by using kinetic Monte Carlo methods, and a database of displacement cascades which were generated by molecular dynamics. Mechanical property changes exhibited by the irradiated material were modelled by using 3-dimensional dislocation dynamics which took account of the spatial distribution of defects produced by irradiation, and of the fate of dislocation interactions with stacking-fault tetrahedra.

Mechanical Property Degradation in Irradiated Materials - a Multiscale Modelling Approach. B.D.Wirth, M.J.Caturla, T.Diaz de la Rubia, T.Khraishi, H.Zbib: Nuclear Instruments and Methods in Physics Research B, 2001, 180[1-4], 23-31