The threshold displacement and interstitial atom formation energy in TiAl alloy

Threshold displacement energies for atomic displacements along some interesting directions, and formation energies of vacancy, anti-site and several symmetric interstitial atom configurations are calculated for a TiAl alloy by a molecular dynamic method using the Finnis-Sinclair many-body potentials in this paper. The results show that, the four possible octahedral configurations are unstable and the Al(Al) [110] crowdion is energetically favored in the five stable interstitial configurations. In most directions the displacement energies for Al PKA are larger than those for Ti PKA, the strength of the interaction potentials is only determinative along [110] and [100], the values of E d of the Ti atom are larger than those of the Al atom. The results also show that the displacement energy along [001] is larger than that along the [100] direction both for the Ti atom and the Al atom.