A THEORY OF DIPOLAR DISLOCATION WALL STRUCTURES

The goal of the paper is to answer three questions: (1) to investigate the way in which the dipolar dislocation walls are formed, (2) to explain their tendency to regular arrangement and (3) to determine their geometry. The answers are based on the linear stability analysis of the proposed model of sweeping and dragging mechanisms of dislocation dipole clustering. From the set of wall orientations provided by the analysis the most stable dipolar dislocation structure actually formed is selected by an energetically motivated geometrical criterion. The model is employed for prediction of geometry of the dipolar wall structures produced by collinear slip belonging to one or two slip planes, coplanar or non-coplanar symmetric double slip, and symmetric multislip. In all cases the predicted wall geometry is consistent with the available observations.