Core structures were proposed, for <¯101] and ½<¯1¯12] non-coplanar C-type and S-type dislocations, where partial dislocations lay on 2 parallel {111} slip planes. Such cores involved 3 parallel partial dislocations, one of which was delocalized on two {111} planes, that delineated 2 regions of stacking fault. A distinction was drawn between glissile and sessile C-type and S-type super-dislocation cores. Glissile cores could permit <¯101] and ½<¯1¯12] super-dislocations to glide in low-energy complexes with small Burgers vector components and no high-energy antiphase boundary, while sessile cores could give rise to dipole formation. Mechanisms for faulted dipole formation and destruction were proposed which involved the glissile ↔ sessile transformation of C-type and S-type super-dislocation cores. The glissile ↔ sessile transition simply required rearrangement of the core of the partial dislocation which was delocalized over 2 parallel {111} planes. Such a transition could not be detected by means of weak-beam transmission electron microscopy.

Glissile Non Co-Planar Super-Dislocations, and Mechanisms of Faulted-Dipole Formation in γ-TiAl B.J.Inkson: Philosophical Magazine A, 1998, 77[3], 715-36