The structures of [001] low-angle tilt boundaries in Ni3(Al0.8Ti0.2) L12 bi-crystals, which had been prepared by hot pressing, were investigated by means of high-resolution transmission electron microscopy. Dislocations with a Burgers vector of a[100] were found which dissociated into 2 super-partials, with Burgers vectors of a/2[110] and a/2[1¯10], connected by antiphase boundary. The dissociated super-partials, and the corresponding antiphase boundary, lay along the grain-boundary plane. The cores of the dissociated super-partials were spread over a few {011} atomic planes.

High-Resolution Electron Microscopy of Grain Boundaries in Ni3(Al0.8Ti0.2) Bicrystals. I. [001] Small-Angle Tilt Boundaries. Emori, H., Takasugi, T., Hiraga, K.: Philosophical Magazine A, 1997, 75[5], 1403-16