Thermodynamics of the Al2O3–SiO2 System: Mullite Melting & Phase Equilibria

How stable is mullite, and when does it melt? This episode explores the Al2O3–SiO2 system using a four-sublattice mullite model, a two-sublattice ionic liquid model with the AlO2⁻¹ species, and Thermo-Calc pressure-dependence to map Al2O3 polymorph phase relations. CALPHAD optimization delivers phase diagrams and thermochemical data that match experiment.