Decay of low-angle tilt boundaries in deformed nanocrystalline materials

A theoretical model is suggested, which describes a decay of low-angle grain boundaries in deformed nanocrystalline materials (NCMs). In the framework of the model, lattice dislocations that form a low-angle boundary are under the action of the forces owing to external (applied) and internal stresses. The balance of the forces causes the critical shear stress at which a low-angle boundary decays. Such decay processes result in the formation of high-density ensembles of mobile lattice dislocations that are capable of inducing plastic flow localization (shear banding) in mechanically loaded NCMs.