Influence of asymmetric rolling on the microstructure, texture evolution and mechanical properties of Al–Mg–Si alloy

Abstract

The influence of asymmetric rolling on the microstructure, texture and mechanical properties of Al–Mg–Si alloy was investigated comprehensively through finite element simulation (FEM), microstructure and texture characterization, and tensile testing. Cold rolling was applied by imposing different velocity ratios (from 1 to 1.75) between the upper and lower rolls. The results show that asymmetric rolling has some effects on the shear strain, microstructure, texture and mechanical properties. The shear strain always exhibits a non-uniform distribution throughout the sheet thickness, and it is closely related to the velocity ratio; improving the velocity ratio could result in a larger shear strain in the surface contacting the roll with a higher velocity. As the velocity ratio increases, the cold rolled alloy sheet contains an increasing number of fine equiaxed grains, and the solution-treated recrystallization grain structure gradually becomes fine. Unlike symmetric rolling, asymmetric rolling can result in the development of TD-rotated β fiber, and the rotation angle is largely dependent on the velocity ratio. Although no ideal shear texture E {111}<110> and F{111}<112> orientations were developed, the shear texture H{001}<110> orientation appears by applying a sufficient velocity ratio. After solution treatment, the velocity ratio has no influence on the texture component, but improving the velocity ratio can reduce the texture volume fraction. Asymmetric rolling plays a positive role in improving mechanical property. As the velocity ratio increases, there are increases in the strength, elongation and plastic strain ratio R, and a decrease in the planar anisotropy ΔR, which is likely attributable to the weak texture.