Thermodynamic assessment within the Zr–B–C–O quaternary system

Abstract

AbstractThermodynamic modeling of Zr–B–C–O quaternary system is conducted within the CALPHAD framework by employing data obtained from first‐principle calculations and literature. The lower order binary B–O is assessed in this work by estimating the thermodynamic properties of stable solid phases of B2O3 and B6O and by estimating the gas and liquid phases. First‐principle calculations, in conjunction with special quasirandom structure were used to predict enthalpies of mixing for the ternary solid‐solution phase of FCC‐Zr(C, O). The calculated results were used to optimize the model parameters pertaining to the cubic phase, which is described by a two‐sublattice model. The modeled Zr–C–O ternary phase diagrams calculated at 1923 and 2273 K under ambient pressure and 4 Pa, respectively, are in agreement with experimental phase diagrams.