Microstructure and mechanical properties of Al-Si-Mg alloys fabricated by twin roll casting and subsequent symmetric and asymmetric rolling

Abstract

Al-Si-Mg aluminum alloys were asymmetrically cold-rolled using differential speed rolling mills. The textural and microstructural evolution with the consecutive working sequence was investigated using an electron backscatter diffraction. There were texture and microstructure variations with the speed ratio and a reduction in the area. Strongly-developed recrystallized cube orientations, {100}‹001›, remained during symmetric rolling. The weakened cube orientation mainly changed into random orientations during subsequent annealing, and a small amount of cube orientations remained. However, during asymmetric rolling with a speed ratio of 2, the shear deformation penetrated through the entire thickness direction, and a strong shear texture of rotated cube, {100}‹011›, developed. The distinct shear texture was recrystallized into {356}‹0 17 14› components. The mechanical properties of the symmetrically- and asymmetrically-fabricated sheets were compared with each other. More balanced planar isotropic values of strength and elongation were obtained from the symmetrically-fabricated sheets, which are mainly due to the weakened random texture.