Evolution of shear texture during the asymmetric rolling and its annealing behavior in a twin-roll casting AA6016 sheet: an ex-situ electron backscatter diffraction study

摘要

To better understand the enhanced formability of Al–Mg–Si alloy automotive outer panels by introducing shear texture F{111}<112> orientations, we investigate the shear texture evolution of a twin-roll casting AA6016 sheet with an initial R-cube and E texture during asymmetric rolling (ASR). The macro-textures of the sheet with a deformation of 30%, 50%, and 85% are studied using X-ray diffraction. Results show that the initial R-cube evolved to Dillamore/copper with the increase in strain, whereas the initial E texture is weakened accompanying the enhancement of the F texture during ASR. Moreover, the local recrystallization textures are analyzed using the sheet that has been annealed at 330°C at different times via the ex-situ electron backscatter diffraction. The F texture is dominant for the ASR sheet, which could be attributed to the rapid nucleation and grain growth of grains with F orientation (F-grains). Furthermore, the spatial relationship at 19.7°[1ˉ10]between the grain with copper orientation and F-grains is another important reason to promote the F orientation development. Finally, the formability of the ASR sheet is found to significantly improve.