HOW ARE NEW ORIENTATIONS GENERATED DURING PRIMARY RECRYSTALLIZATION

High-voltage electron microscopy (HVEM) of in situ recrystallizing sin gle crystals and growth competition experiments, according to Beck,[13 ] have been performed in order to better understand how new orientatio ns develop during primary recrystallization. The specimens used were s ingle crystals of Al, Cu, Cu with Mn, or P additions in order to vary stacking fault energy and size misfit of the solute. Evidently, nuclea tion is always in orientations of the deformed matrix. New orientation s develop by annealing twinning, unless the deformation microstructure (DM) of a rolled polycrystal is already inhomogeneous enough. In both cases, the same fast-growing grain boundaries (GBs) determine the fin al recrystallization texture. These GBs differ depending on purity and solute and can be characterized (and compared with respect to calcula ted structures) by the nearest coincidence site density SIGMA-1.