Grain Boundary Dislocation Structure and Motion in an Aluminum Σ=3 Bicrystal

Abstract

A lattice dislocation may interact with a grain boundary leaving either a residual dislocation or a step or both. These products may then contribute to further deformation by themselves moving along the interfaces. For instance, Pond1 observed the dissociation of a perfect lattice dislocation in an aluminum Σ=3 (211) incoherent twin boundary by a reaction of the type:Furthermore, the a/3[111] dislocation was observed to dissociate into two partial grain boundary dislocations (GBD), with Burgers vectors of approximately 2a/9[111] and a/9[111], separating structurally degenerate regions of opposite rigid body displacement.