| Abstract Scope |
Rare earth (RE) silicate environmental barrier coatings (EBCs) are presently being investigated for application on SiC-based ceramic matrix composites in aircraft turbine engines. RE silicates primary function is to mitigate the volatility of SiO2 and limit the thermally grown oxide (TGO) on the silicon bond coat during operation. In marine combustion environments, Na2SO4 can form molten deposits at temperatures around 884oC, resulting in EBC degradation at potentially lower temperatures than the maximum operating conditions (1300-1400oC). Currently, there is minimal research and understanding of EBC hot corrosion in the presence of molten Na2SO4. This research addresses this knowledge gap by exploring the reactions between Na2SO4 and free-standing air plasma sprayed RE silicate EBC materials, Y2Si2O7, Y2SiO5, Yb2Si2O7, and Yb2SiO5, at 825oC for times up to 250hr where reactions are observed even below the melting temperature of Na2SO4. |