Large-scale fragmentation of grains in plastically deformed polycrystalline iron

Abstract

The large-scale banding is one of the mechanisms of grain fragmentation in cold-deformed metallic materials. In the present study, this phenomenon was studied by means of EBSD in iron deformed by tension. Transition zones of three types have been identified between differently oriented in-grain domains generally known as deformation bands: the narrow or diffused borders consisting of low-angle boundaries, the band-shaped zones with the pronounced crystal fragmentation, and the regions containing families of alternatively misoriented microbands. The underlying heterogeneities of plastic flow resulting in the formation of deformation-induced high-angle boundaries are discussed in terms of polycrystal micromechanics.