Thermodynamic functions of undercooled Fe-P melts

The approaches to calculating the thermodynamic properties of undercooled m elts are critically evaluated. It is shown by the example of the eutectic F e-P alloy that the rough estimates relying on various models of melt struct ure, primarily on the hole theory, provide inadequate results. Based on the concept of associated solutions and the thermodynamic functions of the con stituent components found by solving the inverse problem of chemical thermo dynamics, a procedure is proposed for analyzing the thermodynamic behavior of undercooled melts, in particular, near the glass transition. The thermod ynamic quantities calculated by this procedure coincide with experimental d ata to within the measurement accuracy. The procedure is used to calculate the thermodynamic properties and viscosity of Fe-P melts between the glass- transition temperature (similar or equal to 650 K) and 1873 K. The results are in perfect agreement with experimental data.