Measurement and Thermodynamic Evaluation of Phase Equilibria in the Mg-Ti-O System

The stability of pseudobrookite type solid solutions in the binary section FeTi 2 O 5 -Ti 3 O 5 is investigated in the temperature range 1060° to 1360 °C by the quench method combined with chemical analysis and X-ray diffractometry. These data are then combined with all other available phase equilibrium and thermodynamic data in order to obtain a set of optimized thermodynamic equations for the phases in the FeTiO 3 -TiO 2 -Ti 2 O 3 -Fe system. Models for the ilmenite and pseudobrookite solutions are developed. The good agreement between the calculated phase equilibria and the measurements indicates the essential correctness of the thermodynamic data and the phase diagrams.