Prediction of thermodynamic properties of the C–Fe–Co–Ni solid solutions by binary infinite dilute activity coefficients

A novel molecular interaction volume model proposed by the author can be used to describe the thermodynamic properties of a multicomponent solid solution system using its binary interaction parameters only. A derivation of the model for a common quaternary system has been shown as a compensation of its general expression. The predicted activity coefficients from the model are in good agreement with the experimental data of the C–Fe–Co–Ni solid solution. It shows that the model is of better predictability and reliability in comparison with a fourth-degree polynomial formulism because it has a good physical basis.