|About this Abstract
||2016 TMS Annual Meeting & Exhibition
||Thermodynamic Applications, Optimizations and Simulations in High-Temperature Processes: An EPD Symposium in Honor of Christopher W. Bale's 70th Birthday
||CALPHAD Modeling of Thermochemical Interactions of Thermal Barrier Coatings (TBCs) with Molten Calcium-Magnesium-Aluminum-Silicon Oxides (CMAS)
||Lina Kjellqvist, Huahai Mao, Qing Chen, Johan Bratberg, Anders Engström, Nicholas Hatcher, Weiwei Zhang, Jason Sebastian
|On-Site Speaker (Planned)
Thermal barrier coatings (TBCs) in modern aircraft engines are susceptible to spallation by high temperature attack of molten mineral deposits such as dust, sand, and volcanic ashes that consist mainly of CaO-MgO-Al2O3-SiO2 (CMAS). In order to design novel CMAS-resistant TBCs, thermochemical interactions between CMAS and existing TBCs need to be understood first. The state-of-the-art TBCs is usually made of 7~8% yttrium-stabilized zirconia (YSZ). In this work, a thermodynamic database has been developed for calculating CMAS and YSZ interactions using the CALPHAD approach. Binary through quaternary thermodynamic descriptions in the CMAS-YZ system were incorporated into the database and validated against experiments. The two-sublattice ionic liquid model was used to model the liquid phase. The compound energy formalism (CEF) has been adopted for modeling the solid oxide solution phases. The results have been used to investigate the phase evolution at the CMAS-YSZ interface and establish possible pathways for novel CMAS-resistant TBCs designs.
||Planned: TMS Journal: Metallurgical and Materials Transactions