Melting enthalpy and entropy of binary systems of alloys of 3d transition VII and VIII metals and carbon: Thermodynamic calculation and experimental study

Thermodynamic calculations have been performed of the melting enthalpy and entropy of the Co C, Ni-C,and Fe-C binary system alloys having eutectic com positions and of alloys whose compositions correspond to the minimum temper atures of the Mn C, Fe-Co, Fe-Ni, and Mn Ni melting diagrams. fleet capacit ies of one- and two-phase alloys of investigated systems have also been cal culated as a function of temperature. In order to express a dependence of t he Gibbs energy (G) of the liquid phase on the composition, the model of re gular solutions has been used. The relation between the G of interstitial s olid solutions and concentration was described by the two-sublattice model. The values have been experimentally verified using a high temperature calo rimeter. These results have shown that the discrepancy bt tween experimenta l and calculated results is within the calorimetric measurement uncertainty and does not exceed 10%.