Disclinations in Plastically Deformed Metallic Materials

Abstract

Cold-working of metallic materials up to large strains is usually characterised by simultaneous substructure evolution on different length scales and accompanied by the formation of significant lattice rotations. A promising tool for the description of such microstructure development is the concept of partial disclinations. Transmission electron microscopy (TEM) studies illustrate clearly, that defects of this kind are frequently existent in cold-worked metals and have to be accepted as an important defect entity in the substructure evolution at larger strains. Moreover, it is shown that substructure modelling on the base of a coupled dislocation-disclination dynamics leads to satisfying correspondence of calculated substructure characteristics with experimental results obtained by TEM, X-ray diffractometry, and EBSD (electron backscattering diffraction), and to a satisfying prediction of the macroscopic deformation behaviour, i.e., especially the transition from stage III to stage IV of crystal plasticity.