The Al–B–Nb–Ti system: II. Thermodynamic description of the constituent ternary system B–Nb–Ti

The thermodynamic description of the ternary system B–Nb–Ti is obtained by modelling the Gibbs energy of all individual phases in the system using the CALPHAD approach. The model parameters have been evaluated by means of a computer optimization technique based on the available descriptions of the constituent binary systems B–Nb, B–Ti and Nb–Ti and relevant experimental information on phase equilibria for the ternary system. The thermodynamic descriptions of both systems with boron, B–Nb and B–Ti, were published in the first part of the work. For the ternary system B–Nb–Ti several vertical and isothermal sections as well as the projection of the liquidus and solidus surface are calculated using the elaborated thermodynamic description. A tolerable agreement between the calculations and experimental data is achieved.