Thermodynamic Evaluation of the system Ta–O and Preliminary Assessment of the Systems Al–Nb–O and Al–Ta–O

The binary tantalum–oxygen system is assessed using the CALculation of PHase Diagrams (CALPHAD) method with experimental data from literature. oxygen solubility in Ta solid-solution phase discussed and modeled. low- high-temperature modifications Ta2O5 are described as stoichiometric compounds. This dataset extended into ternary Al–Ta–O by complementing it datasets for Al–O Al–Ta literature adding mixed-oxide AlTaO4. Al–Nb–O created combining three corresponding assessing quasibinary section Al2O3–Nb2O5. aluminum niobates Phase equilibria between refractory metals alumina at high temperature discussed.