Problems in evaluating the dislocation densities in heavily deformed Cu-Nb composites

Abstract

The dislocation density of the Cu matrix in a heavily cold-rolled Cu-20%Nb composite is evaluated as a function of deformation strain. The methods and problems involved in this analysis are described and discussed in detail. The maximum dislocation density was found to be 10 10-10 11 cm -2 at all strains investigated. Dislocations were not uniformly distributed but rather had a low energy dislocation structure. The effects of sample preparation, specifically ion-thinning, were evaluated and found to have little effect on the dislocation population of worked Cu but actually introduced defects into annealed Cu.