Modeling the oxidation kinetics of titanium alloys: Review, method and application to Ti-64 and Ti-6242s alloys

Highlights: • Analytical model predicting mass gain, oxygen affected zone and oxide scale. • Similar oxygen diffusion kinetics in Ti-6Al-4 V and Ti-6Al-2Sn-4Zr-2Mo-Si matrixes. • Differences in oxidation kinetics mainly result from different oxide thicknesses. The oxidation kinetics of Ti-6Al-4V and Ti-6Al-2Sn-4Zr-2Mo-Si were reviewed in the range 450−650 °C. A method to fit these data was conceived and applied to these alloys, allowing the prediction of mass gain, oxygen diffusion coefficient, embrittlement depth and oxide scale thickness. Prediction diagrams are produced and discussed through the prism of aeronautical applications; discrepancies between modeled and experimental data are discussed. This paper shows that despite Ti-6Al-4V experienced larger mass gains than Ti-6Al-2Sn-4Zr-2Mo-Si, the two alloys have an equivalent behavior in terms of oxygen dissolution and diffusion, over a wide range of exposure durations.