Thermodynamic and kinetic modeling of bcc phase in the Ti–Al–V ternary system

A thermodynamic optimisation of the ordered B2 phase in the Ti–Al binary and Ti–Al–V ternary systems is carried out, making use of a two-sublattice model (Ti,Al,V):(Ti,Al,V). A self-consistent set of parameters is obtained; it is demonstrated that the available experimental data for the phase equilibria are reproduced accurately. Based upon the thermodynamic driving forces calculated by the new thermodynamic database, interdiffusion in the disordered A2 phase of the ternary Ti–Al–V system is assessed and optimised. A set of parameters describing the atomic mobilities of the disordered A2 phase are given, which will be useful for future quantitative models of phase transitions involving this phase.

Research highlights▶ Thermodynamic modelling of the Ti–Al–V system is presented. ▶ Emphasis is placed on the assessment of the B2 phase. ▶ The atomic mobilities of the Ti–Al–V ternary system are assessed. ▶ Application of the models allows new grades of Ti alloy to be designed.