The role of shear banding on deformation texture in low stacking fault energy metals as characterized on model Ag crystals

The microstructure and texture evolution during deformation of a representative low-stacking fault energy (SFE) metal was characterized by detailed local scanning electron microscopy and transmission electron microscopy orientation measurements. High purity silver single crystals with an initial (1 1 2)[111¯] orientation were channel die deformed to total reductions of 88% (logarithmic strains 2.1), first developing twin-matrix layers and then compact clusters of two families of shear bands. It was shown that twinning and shear banding caused several important transitions of the deformation textures. The as-deformed shear bands exhibited large orientation spreads of up to 40° with respect to the adjacent twinned areas. Most of these misorientations occurred by rotations about the transverse direction ∥〈1 1 0〉 axis with significant further rotations about 〈1 1 2〉 poles. These two rotations explained the influence of the shear bands on the formation of Goss{1 1 0}〈0 0 1〉 and brass{1 1 0}〈1 1 2〉-S{1 2 3}〈6 3 4〉 texture components, which are clearly observed in highly deformed low-SFE metals. Symmetrically equivalent crystal lattice rotations inside narrow areas led to the formation of the positive and negative macroscopic shear bands for high deformations.