EXPERIMENTAL AND THERMODYNAMIC ASSESSMENT OF THE FE-ZR SYSTEM

The Gibbs energies of formation of the solution and compound phases in the Fe-Zr system were derived from an optimization procedure using al l the available experimental thermodynamic and phase diagram data. The thermodynamic description of the non-stoichiometric compounds was mad e using a two-sublattice model, while a Redlich-Kister polynomial was used for the solution phases. The enthalpy and temperature of fusion, as well as the temperature of invariant reactions were determined expe rimentally by differential thermal analysis. The results derived from the optimization are very satisfactory, despite the sparse data concer ning the phase diagram and thermodynamic properties.