|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||The oxidation behavior of the eutectic alloy Mo-20Si-52,8Ti in dry and wet atmospheres
||Matthias Weber, Bronislava Gorr, Hans-Jürgen Christ, Susanne Obert, Aditya Srinivasan Tirunilai, Alexander Kauffmann, Martin Heilmaier
|On-Site Speaker (Planned)
Mo-silicide based alloys with high Ti concentrations are a new class of high temperature materials with promising properties. The good oxidation resistance relies on the formation of a duplex titania-silica layer. In this contribution, the effect of water vapor on the formation and growth of oxide scales on the alloy Mo-20Si-52.8Ti (at. %) at 1200°C is investigated. The oxidation kinetics increases in wet atmospheres compared to that in dry air. To explore whether the outer TiO2 layer can diminish the detrimental effect of water vapor, this scale was removed which causes a dramatic acceleration of the scale growth kinetics in the wet environment. It is discussed that water vapor may increase the concentration of oxygen vacancies in titania leading to faster inward diffusion of oxygen. Further, the diffusion of water in silica is substantially higher than that of oxygen obviously accounting for the higher oxidation rates in wet atmospheres.
||High-Temperature Materials, Environmental Effects, Other