Thermodynamic Analysis of Martensitic Phase Transformations Observed in Fe–Mn–Si and Fe–Mn–Al–Si Alloys

Abstract

Prediction of thermodynamic properties for ternary Fe–Mn–Si and Fe–Mn–Al–Si quaternary alloys were studied using Chou’s general solution model along with the calculated results of Muggianu and Kohler models. The general solution model was reformulated for quaternary systems. The Gibbs free energies were obtained as a function of temperature from the sum of an excess energy term, a molar Gibbs energy term and magnetic energy term. The equilibrium temperatures were calculated by using the difference between the Gibbs free energy of the fcc and hcp phases for ternary and quaternary systems mentioned above. The calculated results were compared with those obtained from typical models, such as Muggianu and Kohler models and experimental data. It was observed that the calculated results from general solution model are in agreement with those obtained from the experimental data.