Intrinsic values of interfacial energies, based upon first-principles calculations including atomic relaxation, were obtained for the three types of γ/γ interface and α2/γ lamellar boundary in two-phase TiAl alloy. The pseudo-twin boundary energy (270mJ/m2) was highest and the true twin-boundary energy (60mJ/m2) was lowest. Planar fault energies at pseudo-twin and 120°-rotational interfaces were markedly different to those in the bulk of the γ-phase.

Interfacial Energies in Two-Phase TiAl-Ti3Al Alloy. C.L.Fu, M.H.Yoo: Scripta Materialia, 1997, 37[10], 1453-9