| About this Abstract |
| Meeting |
2022 TMS Annual Meeting & Exhibition
|
| Symposium
|
Environmental Degradation of Multiple Principal Component Materials
|
| Presentation Title |
Computational Investigation of the Trends that Govern the Coefficient of Thermal Expansion in Rare-earth Silicates |
| Author(s) |
Mukil Venthan Ayyasamy |
| On-Site Speaker (Planned) |
Mukil Venthan Ayyasamy |
| Abstract Scope |
In applications such as aviation jet engines, where temperatures as high as 1300°C are common in the hottest sections, environmental barrier coatings (EBCs) protect the Si-based ceramic matrix composites (CMCs) gas turbine components from reacting with corrosive salts and water vapor at extreme conditions. The objective of this work is to develop an understanding of the trends that govern the coefficient of thermal expansion (CTE) in rare-earth monosilcates (RE2SiO5) and rare-earth disilicates (RE2Si2O7), which are two key EBC candidates for high temperature applications. In select members of the RE2SiO5 family, our density functional theory (DFT) calculations reveal a correlation between the observed CTE anisotropy and electronic structure. In addition, our DFT work on the polymorphs of a high-entropic RE2Si2O7 system capture the complexities in the local RE-O and Si-O bond geometries. The outcome of this work has major implications in developing design rules for the rational design of EBC materials. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Computational Materials Science & Engineering, High-Temperature Materials, High-Entropy Alloys |