The stacking-fault energy of high-Nb TiAl alloy was reduced by the addition of Nb. The intrinsic stacking-fault energy of Ti-45Al-8.5Nb alloy was about 75 to 85mJ/m2 in the anisotropic condition, and about 59 to 69mJ/m2 in the isotropic condition.

Determination of the Stacking Fault Energy in High-Nb γ-TiAl. X.P.Song, G.L.Chen: Journal of Materials Science Letters, 2001, 20[7], 659-61