Stability of {4 4 11} ⟨11 11 8⟩ Orientation in a {123} ⟨634⟩ Aluminum Single Crystal Processed by Accumulative Roll Bonding

抄録

A pure aluminum single crystal with a (213) [36\bar{4}] orientation was deformed by accumulative roll bonding (ARB) to an equivalent strain of 7.18 under lubricated conditions. The main orientation of the texture in the center layer was (4 4 11) [11 11 \bar{8}]. Two different kinds of crystal rotations were observed to form (4 4 11) [11 11 \bar{8}]; one was the rotation from (213) [36\bar{4}] to (4 4 11) [11 11 \bar{8}] in the center layer, and the other was the rotation from (116) [33\bar{1}] to (4 4 11) [11 11 \bar{8}] when the area changed its position from the surface to the center. The latter rotation is followed by the cyclic ratcheting mechanism proposed by Heason et al. These crystal rotations lead to the stable existence of the (4 4 11) [11 11 \bar{8}] orientation after many ARB cycles. In the present study using the (213) [36\bar{4}] single crystal, the (\bar{4} \bar{4} 11) [11 11 8] orientation was barely found even after an equivalent strain of 7.18. The lack of (\bar{4} \bar{4} 11) [11 11 8] orientation in the center layer is due to the absence of the (001) [110] orientation in the lower surface layer.