Variations in through-thickness recrystallization and grain growth textures in the Al layers in ARB-processed Al/Al(0.3% Sc) composite sheets

• A layered composite of recrystallized pure aluminum and nano-structured aluminum alloy is fabricated by accumulative roll bonding and annealing.
• The deformation and recrystallization textures of the aluminum layers vary along the thickness of the sheets.
• A large grain growth is found in the quarter thickness aluminum layers with a cube oriented texture.
• The nature of deformation and recrystallization texture depends on the differences in hardness between the layers.

This investigation aims to understand the differences in the recrystallization and grain growth textures in aluminum layers along the thickness direction of two layered composite sheets. The sheets were processed by five cycle accumulative roll bonding of commercially pure aluminum and an aluminum alloy containing 0.3 wt.% Sc both in the supersaturated solid solution and artificially aged conditions. Electron back scattered diffraction and transmission electron microscopy were used to characterize the microstructure and crystallography of the rolled and annealed composites. During the early stages of annealing the β-fiber rolling textures remain unchanged and becomes sustained by the so-called continuous recrystallization process. Then, at the completion of primary recrystallization in the later stages of annealing, orientation selective recrystallization occurs and the Brass orientation becomes eliminated. A strong β-fiber primary recrystallization texture was found to be favorable for the secondary recrystallization growth of Cube orientations. Otherwise, conventional grain growth occurs when the primary recrystallization textures have distortions in the β-fiber.

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