Ultrafine microstructure and texture evolution of aluminum foil by asymmetric rolling

AA1060 aluminum foil was rolled from 4 mm to 20 mu m by asymmetric rolling without intermediate annealing. The microstructures and textures were investigated. The original coarse grains with an average grain size of 60 mu m were refined to fine equiaxed grains with an average grain size of about 500 nm with mainly large grain boundaries. During the rolling, the intensities of copper texture C-{112}< 111 > and brass texture B-{011}< 211 > gradually increased, and most crystallites aggregated along the beta and tau orientation lines. The orientation intensity reached the maximum value 26 when the foil was rolled to 500 mu m, but significantly decreased to 16 when the thickness became 20 mu m, and the texture mainly consisted of a rotation cubic texture RC-{100}< 011 >. With the combined forces including drawing, compressing and shearing, severe plastic deformation was obtained during the asymmetric rolling, promoting dynamic recrystallization at room temperature. Because of a combined force in the deformation zone and shear force along the normal direction, dynamic recrystallization occurs during the asymmetric rolling; therefore, the average grain size is significantly refined. The texture intensity of ultrathin strip first increases, i.e., work hardening, and then decreases mainly because of dynamic recrystallization.