Microstructure and texture evolution of Al during hot and cold rolling

Abstract

The evolution of microstructure and texture of commercial purity Al during hot and cold rolling has been studied. The results show that the dynamic restoration mechanism for Al rolled to a total equivalent strain of 2.66 at a mean equivalent strain rate of 14.4 s-1 at 510 °C is essentially dynamic recrystallization (DRX), whereas for those materials deformed to lower strains at lower strain rates at this temperature, the restoration mechanism is mainly dynamic recovery (DRV). This is confirmed by examining the microstructures, textures, and substructures of the material developed during hot rolling as well as by comparing the results with those developed during cold rolling and annealing. The texture analysis using orientation distribution functions (ODFs) indicates that the dynamically recrystallized material has a random orientation distribution, whereas dynamically recovered materials have a developed deformation texture with a predominantD component and a Cu component. The substructure observation by transmission electron microscopy (TEM) indicates that the subgrains in the dynamically recrystallized material are completely dynamically recovered, which is very similar to those subgrains in cold-rolled material. However, the annealed material shows a completely different substructure. By studying all of these structural features, which are closely associated with the dynamic restoration mechanism, it is confirmed that Al undergoes DRX in the present work, which is different from either DRV or static recrystallization (SRX).