Grain growth at fragmentation stage in commercial purity aluminium deformed by high pressure torsion

Abstract

The mechanism for grain boundary motion at the fragmentation stage of high pressure torsion still remains uncertain as measuring grain growth velocity in such stage is challenging. A new approach is proposed in this study to calculate the grain growth velocity in the fragmentation stage. The high grain boundary motion rate and the low apparent activation energy indicate the mechanism for coarse grain growth in commercial purity aluminium in the fragmentation stage at low homologous temperature is attributed to stress-induced boundary motion rather than discontinuous dynamic recrystallization.