Dynamic grain growth in superplastic AA5083

During 'superplastic' deformation of AA5083+Cr, the grain size increases and grain elongation occurs. Several theories for this behaviour have been proposed, but it can be rationalised simply by considering the geometric effect of deformation on a Zener- pinned grain structure. This effect has been modelled by both 'Network' and 'Monte Carlo -Potts' techniques, both of which give results roughly similar to the experimental observations. The effect is complicated by coarsening of the particulate at high temperatures, which leads to static grain growth and an enhanced rate of dynamic grain growth, but this can be included, approximately, in the numerical models.