Orientation perturbations near triple junctions in a non-cell forming aluminium-magnesium alloy

The orientation perturbation behaviour near triple junctions in a deformed Al-3wt.%Mg alloy has been investigated using electron back-scatter diffract ion by performing line scan measurements both perpendicular and parallel to grain boundaries within a distance of 15 mu m from the triple junction. Cr ystal orientation map's were also generated to identify local orientation p erturbations and to reveal the spatial distribution of domain boundaries. T he effect of grain orientation on the degree of perturbation and the presen ce of grain boundary zones are also investigated. The orientation perturbat ions followed three characteristic patterns: (i) perturbations were present near the triple junction only; (ii) perturbations were present near the tr iple junction and within the grain interior and (iii) no perturbations were displayed either near the triple junction or within the grain interior. En hanced zones of perturbation were also observed near triple junctions, the frequency and magnitude of which increased with strain. There was no appare nt relationship between grain orientation and the degree of perturbation al though the results did imply that for individual grains, perturbation level s are influenced by the crystallographic orientation of the neighbouring gr ains. (C) 2000 Elsevier Science S.A. All rights reserved.