Dislocations

Abstract

(1) A distortion produced by translation of the lattice by d/2, i.e., nonintegral multiple of the separation distance between two planes [Weertman and Weertman, 1964]. The resulting imperfection in the translational periodicity may be in the form of a line that lies in the plane of translation. The lattice points near the line are distorted. If the translation occurs perpendicular to the line, the dislocation is edge type. If the translation occurs parallel to the line, the dislocation is screw type. (2) A shear applied to a lattice results in slip. The boundary of the slipped region is called a shear dislocation; the displacement is b; the dislocation can be edge or screw type [Hirth and Lothe, 1984].