| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Thermodynamics of Materials in Extreme Environments
|
| Presentation Title |
Stability of Multicomponent Rare Earth Silicates for Environmental Barrier Coating Application |
| Author(s) |
Mackenzie Ridley, Cameron Miller, Rebekah Webster, Hans Olson, Alejandro Salanova, Kathleen Tomko, Jon Ihlefeld, Cormac Toher, Patrick Hopkins, Elizabeth Opila |
| On-Site Speaker (Planned) |
Elizabeth Opila |
| Abstract Scope |
Environmental barrier coatings (EBCs) are required for application of SiC-based ceramic matrix composites (CMCs) in hot section turbine engine applications. State of the art EBCs are composed of ytterbium silicates. Multicomponent rare earth silicates offer the opportunity to reduce the thermal conductivity of the EBCs via phonon scattering mechanisms, reducing the surface temperatures of the underlying CMCs. The stability of these multicomponent rare earth silicates in high-temperature steam and calcium magnesium aluminosilicate (CMAS)-containing environments relevant for turbine environment were tested at temperatures between 1200 and 1400C. It was found that multicomponent rare earth silicates enable stabilization of nonequilibrium polymorphs, formation of nonequilibrium steam reaction products, and enhanced CMAS resistance. The tailoring of thermal and thermochemical properties of EBCs through choice of rare earth silicate component mixtures is described. |