Model of formation of broken dislocation boundaries at joint disclinations

We propose a physical model of formation of broken dislocation boundaries (partial disclinations of deformation origin) at the joints of large-angle grain boundaries. The model explains why and how rotational-type defects are necessarily formed in polycrystals in which plastic deformation at the microscopic level occurs exclusively via translational slips for strains $\varepsilon>$ 0.2.