The antiphase domain boundary structures within several rapidly-solidified alloys based on Ni3Al were examined both in the as-quenched state and after heat treatments. The domain boundary energy shows a mild anisotropy, as deduced from the shape of the domains. The degree of anisotropy increased with the equivalent aluminum content of the alloy. Slightly deformed materials contained super-dislocation pairs whenever domain boundaries were absent and single dislocations wherever domain boundaries occur. The super-dislocations lay predominantly on {100} planes where glide could also take place. Super-dislocations dissociated into two separate single dislocations upon meeting a domain boundary, leading to significant strengthening and improvement of ductility.

Antiphase Domain Boundaries and their Importance for Dislocation Behaviour in Ni3Al Based Alloys. Morris, D.G., Morris, M.A.: Philosophical Magazine A, 1990, 61[3], 469-91