Role of S[(123)〈634〉] orientations in the preferred nucleation of cube grains in recrystallization of FCC metals

Abstract

The rival theories of Oriented Nucleation (ON) and Oriented Growth (OG) for the formation of strong recrystallization textures on the annealing of deformed materials has been actively disputed for many years. The classic ON hypothesis is that the predominant orientations in the recrystallization texture, for example ``Cube`` [{l_brace}001{r_brace} ] in rolled fcc metals, nucleate much more frequently than other orientations--giving a significantly higher than random frequency of Cube nuclei. The classic OG hypothesis of Cube recrystallization texture assumes that the Cube grains grow faster and thus larger than other grains. Recent studies on cold-rolled high purity aluminum and warm plane strain extruded commercial purity aluminum have given very clear evidence of ON, but found little or no size advantage for the Cube grains. Somewhat similar observations, at least regarding the high nucleation rate of Cube grains, has been reported for cold-rolled high purity copper. There is now a need to address the question as to the mechanism or mechanisms by which the observed preferential nucleation of Cube grains takes place.