The formation process of cube texture during the final annealing in high-purity aluminum foil

The purpose of the present work is to clarify the factors that cause the difference between the 99%-foil and the 98%-foil in volume fraction of cube component in high-purity aluminum foils for electrolytic capacitors. The growth behavior of the cube-oriented grains during the final annealing was investigated in detail using SEM-EBSP technique. A remarkable difference was seen in grain size and distribution of the cube and R components between the two foils at the heating point of 300°C during the final annealing. On the basis of these results, the formation process of the residual non-cube grains are controlled by the difference in the grain size distribution of cube grains after primary recrystallization is discussed. It was thought that the maximum grain diameter is an influential factor in the process, and it depends on the thickness of the foil. Furthermore, it was discussed that the size distribution of cube-grains after primary recrystallization is affected by the factors that exert influence on the driving force of grain boundary movement. These factors are the heating rate in the final annealing, the reduction rate in light-rolling and particularly the size distributions of cube nuclei formed after the intermediate annealing.