Weak-beam transmission electron microscopic analyses were made of ½<112> super-dislocations in order to determine the stacking-fault energies in Ti-45Al, Ti-49Al, Ti-45Al-10Nb and Ti-49Al-10at%Nb alloys at 900C. In Al-poor binary TiAl alloys, the self-interstitial stacking-fault energy decreased significantly with decreasing Al concentration in the γ-phase: from 97mJ/m2 at 49.6%Al to 64mJ/m2 at 48%Al. The ternary alloys exhibited a relatively low self-interstitial stacking-fault energy (about 68mJ/m2) which was almost independent of the Al concentration.

Weak-Beam TEM Study of Planar Fault Energies of Al-Lean TiAl-Base Alloys. W.J.Zhang, F.Appel: Materials Science and Engineering A, 2002, 334[1-2], 59-64