Deformation bands, the LEDS theory, and their importance in texture development: Part I. Previous evidence and new observations

The present state of knowledge regarding '"regular" deformation bands (DBs) is reviewed in the light of some recent observations on DBs in compressed polycrystalline aluminum. These are slablike volume elements within which d ifferent selections of slip systems operate, always fewer than required for homologous deformation, in opposition to the assumption that grains deform as units which are common to all, the Sachs, the Boas and Schmid, and the Taylor/ Bishop and Hill models. The need for a better integration of this k nowledge with not only the origin of deformation textures but also more gen erally with the theory of plastic deformation is pointed out.