Deformation banding in (001)[110] textured aluminium sheet deformed in tension

Deformation banding in (001)[110] textured polycrystalline aluminium sheet material, deformed in uniaxial tension at room temperature, was studied using X-ray texture measurements, transmission electron microscopy (TEM) and electron back scattering patterns (EBSP) in a scanning electron microscope (SEM). The results do not support the concept of deformation banding suggested for very similar experimental conditions in the literature. Instead, the observed characteristics of deformation banding are similar to those reported for (001)[110] oriented aluminium single crystals subjected to plane strain compression. Individual grains were observed to rotate at different rates despite a very strong initial texture and homogeneous macroscopic deformation. A majority of these grains gradually split during tensile straining into two orientation groups that rotate in opposite directions about an axis close to the transverse direction. These regions finally approach the complementary stable copper texture components having a morphology of alternating layers divided by rather sharp planar boundaries approximately parallel to the sheet plane. A possible mechanism of microstructure evolution, leading to the formation of the above layers (deformation bands), has been suggested on the basis of the experimental results obtained. This mechanism does not involve the formation of macroscopic transition layers, characterised by gradual changes in orientation, which is sometimes suggested for single crystals in the literature.