Transformations of grain boundaries due to disclination motion and emission of dislocation pairs

A theoretical model is suggested which describes changes of grain boundary misorientation parameters in plastically deformed polycrystalline and nanocrystalline materials. In the framework of the model, the changes occur via grain boundary disclination motion associated with emission of dislocation pairs from grain boundaries into adjacent grain interiors. Energetic characteristics of the disclination motion in question are calculated.