Dissociated grain boundary dislocations in some incoherent twin boundaries

Abstract
It is shown that partial grain boundary dislocations (GBDs) form two of the three independent arrays of secondary GBDs in incoherent Σ3 boundary facets on {421}/{1085} planes in a f.c.c. Cu+6at%Si alloy. Two states of rigid-body displacement between the grains exist at these interfaces and these rigid-body displacements, together with the Burgers vectors of the partial GBDs, arc determined. The difference in grain boundary energy between the two states of rigid-body displacement is estimated as 2·5 mJ m−2 from the determined Burgers vectors and the measured separations of the partial GBDs.