Hot Corrosion of Rare Earth Silicate Environmental Barrier Coatings.
Abstract
Rare Earth (RE) silicate EBCs are state-of-the-art coatings needed for use of SiC-based ceramic matrix composites in hot sections of turbine engines. The stability of RE silicates with the combustion environment and ingested debris are the topic of current research activities. However, the stability of these coatings with molten Na2SO4, which can form from NaCl and sulfur contaminants in the marine turbine environment, has not yet been addressed. The technical objective of the proposed effort is to address this gap by: i) Probing the Na2SO4(l)-induced hot corrosion behavior of RE Silicate EBCs as a function of time, temperature, and SO3(g) pressure, focusing on state-of-the-art Air Plasma Sprayed (APS) Yttrium- and-Ytterbium Silicates; ii) Identifying the key parameters that control the hot corrosion rate of RE Silicate/CMC systems; iii)Developing methodology for a relevant life prediction model for hot corrosion of RE Silicate EBC/CMC systems; and, iv) Identifying the critical factors that optimize Na2SO4-resistance of EBCs. The work will be accomplished through a series of furnace exposures of RE silicates in controlled environments relevant for Navy use, followed by coating characterization using various microscopy and spectroscopy techniques to establish degradation mechanisms.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 26, 2018
- Source ID
- N000141812628
Entities
People
- Elizabeth Opila
Organizations
- Office of Naval Research
- United States Navy
- University of Virginia