The mechanism of slip band growth in irradiated crystals

Abstract

It has been observed that the slip bands formed in irradiated copper crystals during deformation show an initial phase of rapid development, followed by a slower phase. It is shown that the observed characteristics can be qualitatively explained in terms of the conditions existing at the edges of a band due to (a) partial sweeping of the defect clusters and (b) the elastic stresses due to the work-hardened dislocation structure within the band. The model proposed suggests that the correct parameter to use for the ′strain rate′ in analyses of the thermal activation characteristics of deformation in such materials is the rate of formation of new slip bands, and not the true strain rate of the material within the bands.