Dislocation Cores and Unconventional Properties of Plastic Behavior

Abstract

Dislocations are line defects found in all crystalline materials and their motion produces plastic flow. The notion of dislocations has two starting points. First, the dislocation was introduced as an elastic singularity by considering the deformation of a body occupying a multiply connected region of space. Secondly, dislocations were introduced into crystal physics when analyzing the large discrepancy between the theoretical and experimental strength of crystals. These two approaches are intertwined since the crystal dislocations are sources of long-ranged elastic stresses and strains that can be examined in the continuum framework. In fact, the bulk of the dislocation theory employs the continuum elasticity when analyzing a broad variety of dislocation phenomena encountered in plastically deforming crystals [ 1 – 4 ].