About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
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| Presentation Title |
The Thermochemical Stability of Rare Earth Oxides and Silicates for Thermal/Environmental Barrier Coating Applications |
| Author(s) |
Mackenzie Ridley, Kristyn Ardrey, Cameron Miller, Kate Tomko, Mahboobe Jassas, Kang Wang, Mukil Ayyasamy, Prasanna Balachandran, Bi-Cheng Zhou, Patrick Hopkins, Elizabeth J. Opila |
| On-Site Speaker (Planned) |
Elizabeth J. Opila |
| Abstract Scope |
Rare earth oxides are among the most thermochemically stable oxides making them desirable as thermal/environmental barrier coating materials in high temperature reactive environments such as turbine engines. Rare earth silicates can be visualized as assemblages of rare earth oxides and silicon-oxygen tetrahedra. The rare earth oxides and silicates exhibit a large number of polymorphs due to the variation in rare earth cation sizes existing for the seventeen rare earths. In this presentation, the many crystal structures for the rare earth oxides and silicates will be described in terms of the rare earth – oxygen coordination polyhedral. Trends for thermal properties as well as the phase stability of monosilicates, disilicates, apatite phases and rare earth oxides in high temperature steam and molten calcium magnesium aluminosilicates present in combustion environments will be related to periodic trends. Possibilities for optimizing properties via synthesis of multicomponent rare earth oxides and silicates are described. |
| Keywords |
Computational Materials Science & Engineering, |