It was found that production of ears in deep drawing of aluminum sheets depended upon many factors such as chemical composition, heat treatment, reduction ratio, etc. Especially, in 2S aluminum, ears varied according to the content ratio of Fe/Si.
The investigation of ears was undertaken for 5 sorts of aluminum sheets having the following ratios of Fe/Si: 5, 1.53, 0.39, 0.29, and 0.19, Then, the relation between ears and aggregate structure was also investigated in this study.
The results obtained were summarized as follows.
(1) Columnar crystals in slabs were longer when the ratio of Fe/Si was smaller.
(2) In aluminum sheets having Fe/Si ratio of 0.39, ears were produced in 0-90°direction. However, in other sheets, they were produced in 45°direction at above recrystallization temperature. With respect to the total content of (Fe+Si), the direction of ears shifted to 0-90°with the higher purity of 2S aluminum. These results corresponded well with those of pole figures.
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