Thermodynamic Evaluation and Optimization of the CaO-TiO2-SiO2 Ternary System.

The thermodynamic equilibrium of the CaO-TiO2-SiO2 system plays a crucial role in the design of ceramic materials. CaO-TiO2-SiO2 ternary systems were thermodynamically evaluated and optimized using the CALculation of PHAse Diagram (CALPHAD) method. The liquid phase was modeled with the ionic two-sublattice model, represented as (Ca+2,Ti+2,Ti+3)P(O-2,Va,O,TiO2,SiO2,SiO4-4)Q, and the ternary compound was described using the compound energy formalism (CEF) model. A set of self-consistent thermodynamic parameters was obtained for the CaO-TiO2-SiO2 system. The complete parameters are listed, which reliably could describe the phase equilibria and thermodynamic properties of the ternary system. This thermodynamic description provides a valuable foundation for developing larger thermodynamic databases for multicomponent silicate systems.