On the modelling of the point defects in the ordered B2 phase of the Ti-Al system: Combining CALPHAD with first-principles calculations

▸ We have studied the formation of point defects in the ordered B2 phase in the Ti-Al system. ▸ Enthalpy of formation of vacancies and anti-site atoms was calculated using DFT. ▸ Concentrations of point defects at finite temperatures were calculated using first-principles. ▸ The Gibbs energy model of the B2 and A2 phases was revised to include vacancies. ▸ Ti anti-sites in the Al sublattice and vacancies in the Ti sublattice are the dominant point defects.