Dislocation behaviour during anelastic strain recovery in zinc single crystals prestrained under basal glide

Abstract

Anelastic strain recovery experiments of zinc single crystals strained under basal glide were performed as a function of the forest pyramidal dislocation density at room temperature. The instantaneous strain recovery of specimens unloaded after prestraining in compression is proportional to lγ p 1.8 where l is the average spacing between forest dislocations and γ p is the prestrain. It is suggested that the instantaneous strain recovery results from the back motion of basal dislocations which multiplied under prestraining. The basal dislocations move to back under the influence of the internal stress unless they are impeded by intersection with forest dislocations. The time dependent strain recovery was measured on all specimens in either the unloaded or partially unloaded states, which enabled the activation volume of the process to be determined. The time dependent strain recovery is explainable in terms of the thermally activated back motion of basal dislocations via cutting the forest dislocations.