Study on the Recrystallization Diagram of High Purity Aluminium (1st Report). Effect of purity

Abstract

No systematic investigation of recrystallization diagram to have been carried out on the high purity aluminium. The authors seems investigated the recrystallization diagrams of the high purity aluminiums with a purities of 99.998, 99.992 and 99.92%, comparing with the commerical aluminium (99.5%) to determine the coarsining range. In the case of the initial sheet annealed at 550° which is usually adopted it was found that the coarsening phenomenon took place in the lower rolling reduction less than 5%, as expected in all pure aluminiums. On the other hand, in the case of the initial sheet annealed at 350° from the standpoint of practice, it was found that a remarkable coarsening took place only in 99.92% Al and its range seems to be limitted within the purities from 99.991 to 99.985%, And its coarsening did not take place in lower reduction less than 5% as expected, but it did in higher reduction such as 10∼45%. Another coarsening phenomenon was observed in 99.5% Al which had undergone a heavier reduction, of 45∼65%.