|About this Abstract
||Materials Science & Technology 2019
||Sandphobic Thermal/Environmental Barrier Coatings
||Multlayer, Multifunctional, Thermo-structural Coatings to Mitigate Molten Silicate Attack in Aeroengines
||Sanjay Sampath, Edward Gildersleeve
|On-Site Speaker (Planned)
The need for higher gas turbine operating temperatures has necessitated developments in new thermal and environmental barrier coatings(TBC/EBC). With increasing operating temperatures comes the possibility for ingested siliceous debris (CMAS) to become molten and adhere to the surface of coatings. Depending on the coating microstructure, these molten debris can flow freely into coating or be arrested at the surface via reaction. Of interest are yttria stabilized zirconia (YSZ) and Gadolinium Zirconate (GDZ), which elicit these two disparate interactions. Beyond their unique interaction with CMAS, the inherent microstructure of the coating will have an additional role on the movement of the melt. For example, coatings with high porosity (>15%) or coatings which are dense with vertical cracks (DVC) will have different penetration mechanisms. This study seeks to understand this interplay between the molten CMAS flow and the process-induced microstructure. A multilayer “onion-peel” strategy is proposed as potential mitigation for multi-attack scenarios.