TEXTURE RANDOMIZATION BY INTENSE SHEARING IN LAYERED Al AND AL (0.3Sc) ARB-PROCESSED SHEET

摘要

High purity Al sheet was roll bonded with Al containing 0.3% Sc in the supersaturated solid solution (plus aged) condition, to up to five ARB cycles. The layers in the roll bonded samples remained reasonably straight when bonding was achieved in the supersaturated solid solution condition of Al(Sc), but became curved by intense shearing when pre-aged Al(Sc) was roll bonded. This behaviour was explained by differential strengthening characteristics of the candidate materials. In both Al and Al(Sc) layers, the deformation substructures are dominated by well-developed lamellar bands of different fineness; in Al and Al(Sc) layers the band thickness are 0.7-1.00μm and 0.2-0.4μm, respectively. Extended annealing for 6h at 350 °C led to reerystallization and growth to full layer thickness in the Al layers and extended recovery to generate a 0.5-0.8 μm relaxed subgrain structure in the Al(Sc) layers. The reerystallization textures in the Al layers in the supersaturated ARB sheet was determined to be Brass-free (3 fibre, tending towards a random distribution in the aged ARB sheet.