Model Prediction of Thermodynamic Properties of Co-Fe-Ni-S Mattes

The modified quasichemical model for short-range ordering has been used to predict the thermodynamic properties of liquid Fe-Co-S, Ni-Co-S, and Fe-Ni-S solutions based only upon parameters obtained from critical optimization of data for the corresponding metal-sulfur and metal-metal binary systems. Calculated equilibrium sulfur pressures over the ternary solutions and calculated tie-lines between the ternary solutions and the solid alloy phases agree with measurements, within experimental error limits, over a wide range of compositions and temperatures.