The theory for the evolution of recrystallization textures has, however been controversial. There are two rival hypotheses to explain the evolution of recrystallization textures, one is the oriented nucleation hypothesis and the other is the oriented growth hypothesis. The present work attempts to resolve this dispute by studying the evolution of cube texture in a commercial purity aluminum alloy, ALCOA's PO815. The electron backscattering pattern (EBSP) technique has been employed to determine the crystallographic orientation of individual recrystallizing grains.; Recrystallization of the warm deformed aluminum was selected for detailed study. Very high densities of cube grains were formed in the early stages of recrystallization. For example at 10% recrystallization 76% of cube nuclei were found compared to the expected random frequency of 4%. Cube oriented new grains were no larger than the new grains of other orientations. Even in the fully recrystallized condition the cube grains were no larger in size compared to grains with other orientations. The cube grains were found to nucleate within cube oriented deformation bands. The bands of cube oriented deformed material that were the source of the cube nuclei were spaced about 200-300 {dollar}mu{dollar}ms apart--a spacing comparable to the final recrystallized grain size. The orientation of the deformed material adjacent to the cube bands was also studied but no significant correlation could be found. There was also no clear correlation between those cube bands that gave many cube nuclei and the orientation of the adjacent deformed material. In particular the S-component which is 40{dollar}spcirc{dollar} about {dollar}langle 111rangle{dollar} from cube was not particularly associated with cube bands giving many nuclei.; The intensity of cube texture measured by EBSP in the partially recrystallized sample gave pole figures and ODFs that showed a strong cube texture intensity that was actually somewhat higher than the intensity observed in the fully recrystallized samples measured either by EBSP or X-ray methods. This fall in cube intensity may be associated with the result, obtained here from studies of recrystallization kinetics, that further nucleation of new grains occurred during the later stages of recrystallization. (Abstract shortened with permission of author.)
展开▼