Thermodynamic modelling of the Mg–Ca, Mg–Sr, Ca–Sr and Mg–Ca–Sr systems using the modified quasichemical model

• Published in: Calphad 2008-06, Vol.32 (2), p.240-251
• Main Authors: Aljarrah, M., Medraj, M.
• Format: Article
• Language: English
• Subjects: Computer simulation; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Magnesium; Materials science; Mathematical models; Mg alloys; Mg–Ca–Sr system; Modified quasichemical model; Phase diagrams; Phase diagrams and microstructures developed by solidification and solid-solid phase transformations; Phase diagrams of metals and alloys; Phase transformations; Physics; Solubility; Ternary phase diagram; Thermodynamic properties; Thermodynamics
• ISSN: 0364-5916; 1873-2984
• DOI: 10.1016/j.calphad.2007.09.001

In this work, a thermodynamic description of the Mg–Ca–Sr system is carried out using the modified quasichemical model. The three binary systems Mg–Ca, Mg–Sr and Ca–Sr have been reoptimized based on the experimental phase equilibria and thermodynamic properties available in the literature. Good agreement was obtained among the calculated phase diagrams, thermodynamic properties and the corresponding experimental data from the literature. Using the established database, the Mg–Ca–Sr phase diagram is calculated. Also, a comparison between the liquidus projection calculated using random solution model and the modified quasichemical model is presented. Since experimental data on the mutual solubility between Mg 2Ca and Mg 2Sr could not be found in the literature, the Mg–Ca–Sr phase diagram is calculated and compared for the two cases of limited and complete solubility between these two compounds.