A thermodynamic description of the C–Hf–Ta system over the whole composition and temperature ranges

Abstract Based on a critical evaluation of the literature data, the C–Hf–Ta ternary system has been 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 composition and temperature ranges. The C–Hf and C–Ta systems are remodeled and combined with the description of the Hf–Ta system to assess the C–Hf–Ta ternary system. A self-consistent thermodynamic description for the C–Hf–Ta system has been developed. Comprehensive comparisons between the present calculations and measured phase diagrams show that the reliable experimental information is satisfactorily accounted for by the present thermodynamic description. The liquidus projection and reaction scheme of the C–Hf–Ta system have also been presented.