Influence of symmetric and asymmetric rolling on texture evolution of work-hardened AA 5xxx aluminium alloy

Abstract

The textures and microstructures of hot- and cold-rolled sheets of an AA 5454 aluminium alloy were studied, with special attention paid to comparing the texture development for the symmetric and asymmetric cold rolling. Scanning electron microscopy with electron-backscatter diffraction was used to monitor the development of the microstructure in the differently deformed and additionally annealed samples. Details of the formations and transformations of individual texture components occurring during the rolling processes were observed and discussed. The average grain sizes, textures and mechanical properties were correlated and explained for the symmetric and asymmetric cold-rolled samples. The asymmetric rolling is beneficial in terms of deep drawability because it reduces the planar anisotropy of the annealed material due to the decrease of the Cube, Goss, rotated-Cube and η-fibre texture components and at the same time strengthens X1- and X2-fibre texture components which are shear texture components and improve deep drawability. During the asymmetric cold rolling, the temperature increases due to friction, triggering recrystallisation processes and leading to larger grains. It is also confirmed that asymmetric cold rolling uses less rolling force and consequently less energy to produce a final material with better formability, particularly earing.