Super-dislocations of the <110>{111} system in monocrystalline material were studied by means of weak-beam transmission electron microscopy. It was found that the super-dislocations dissociated into superlattice intrinsic stacking fault coupled (1/3)<112> super-partials at 77K, but into antiphase boundary coupled (1/2)<110> super-partials at 1028K. This transition in dislocation structure suggested that the antiphase boundary energy decreased with increasing temperature, as previously suggested. The shape of the critical resolved shear stress versus temperature curve, which decreased sharply with increasing temperature at low temperatures and which was almost temperature independent at high temperatures, was also in agreement with this observation.

Plastic Deformation of Chromium-Modified L12 Al2Ti - II. Weak-Beam Transmission Electron Microscopy Study of Dislocation Structures. Z.L.Wu, D.P.Pope, V.Vitek: Philosophical Magazine A, 1994, 70[1], 171-83