On recrystallization nucleation in pure aluminum

Static recrystallization is an important aspect of metal processing. The initial stage of recrystallization - nucleation of new grains - determines its later stages. The accepted mechanisms of recrystallization nucleation are based on the assumption that embryos with orientations of the nuclei preexist in the deformed matrix. However, this standard picture seems to be incomplete. There are indications that, in some cases, the deformed matrix has no orientations observed in recrystallized material. Therefore a mechanism of early stage recrystallization without preexisting embryos is considered. Since the recrystallization growth shows strong orientation selection, and the recrystallization front is believed to migrate through collective shuffling of atoms, it is postulated that the shuffling mechanism responsible for oriented growth of a recrystallizing grain extends to the very beginning of the grain's existence, i.e., that a new orientation can be created via rearrangement of atoms in a strained region. The postulate explains the formation of new orientations, and it has the potential to significantly change the understanding of the early phase of recrystallization.