Mixing Enthalpies of Liquid Alloys and Thermodynamic Description of the Cu–Fe–Co System

Abstract

The mixing enthalpies of ternary liquid alloys of the Cu–Fe–Co system have been studied by calorimetric method at 1873 K and x_Co = 0–0.55. The thermodynamic assessments of the Fe–Co and Cu–Fe–Co systems have been carried out in the frameworks of the CALPHAD method. The set of self-consistent parameters of thermodynamic models of the phases has been obtained taking into account data on the mixing enthalpies measured in the present work and information on the phase transformations. The isothermal and polythermal sections of the phase diagram, liquidus, solidus and metastable miscibility of the supercooled liquid alloys surfaces have been calculated. The undercooling degrees for the metastable liquid phase separation and temperature-composition limits of the formation of the supersaturated solid solutions during the liquid quenching have been assessed.