Relation between ridging and texture components in Al-Mg-Si alloy

Al-Mg-Si alloy is the suitable material for the automotive body application. However, it is found that a rope-like profile (ridging) develops when the Al-Mg-Si alloy sheet is stretched along the transverse direction. In this study, in order to clarify the formation process of ridging developed in Al-Mg-Si alloy, the relation between ridging and texture components of the sheet was investigated by 3D profile microscope and SEM/EBSD method. It was found that the ridging developed remarkably in the hot-rolled (at higher temperature) and annealed sheets. In ridging sample, there was the band of cube oriented grains (cube band). It was also found that the region of cube band corresponded to the ridges and valleys which caused a rope-like profile in the sheets. It could be thought that the difference of plastic deformability between cube-oriented grains and other oriented grains led to the development of ridging. This assumption is supported by the lower Taylor factor of cube oriented grains than other oriented grains. From these results, it was concluded that the development of ridging was strongly affected by the distribution of cube oriented grains.