A thermodynamic description of the C–Ta–Zr system

•The C–Ta–Zr ternary phase diagram is calculated over the entire composition and temperature range.•The liquidus projection and reaction scheme of the C–Ta–Zr system are presented.•The miscibility gap of cubic (Ta,Zr)C at low temperatures is thermodynamically predicted.

Based on critical evaluation of the literature data, the C–Ta–Zr ternary system has been reviewed and assessed by means of the CALPHAD technique. There is no ternary compound in this system. The individual solution phases, i.e., liquid, fcc, hcp and bcc, have been modeled. The modeling covers the whole compositional range of this system and the temperature range from 200 to 3600 °C. A self-consistent thermodynamic description for the C–Ta–Zr system has been developed. Comprehensive comparisons between the present calculations and measured phase diagrams in the literature show that the reliable experimental information is satisfactorily accounted for by the present thermodynamic description. The liquidus projection and reaction scheme of the C–Ta–Zr system have been presented.