Deformation (Dislocations)

Definition

Deviations from the strictly geometrical lattice structure (Schmid and Boas 1950). Alternatively, an interfacial region whose advance causes a fully slipped region to grow at the expense of an unslipped region (Cottrell 1967).

Theory and Application

Introduction

Large plastic deformation can be identified by the accumulation of slips at the macroscopic scale as well as at the atomic scale. During tensile deformation, metal blocks slip on slip planes and rotate, as schematically illustrated in Fig. 1. Increasing plastic deformation results in numerous cross slips. Such slips can be observed as Lüders bands in annealed low-carbon steel subjected to tensile deformation. From the macroscopic viewpoint, this is a visible example that proves that plastic deformation involves the accumulation of slips on slip planes. Such slips at the atomic scale are called dislocations, which are deviations from the strictly geometrical lattice structure (Schmid and Boas 1950). Dislocations are...