Silicon Nitride Seal for Thermal Barrier Coating in Gas Turbines for Extended Engine Life

Cerium Labs is reporting the results of its STTR Phase I funding for a silicon nitride seal for thermal barrier coating in gas turbines for extended engine life. Gas Turbine Engines (GTEs) operate at high temperatures, submersed in a high density gas. Thermal Barrier Coatings (TBCs) are widely used to protect the engine superalloys from oxidation and other degradation. A breakdown in TBC coating allows the engine superalloy to be corroded and engine performance degrades. With an AFWERX Open Topic STTR (X20.A, Award FA864920P0565), we explored a patented silicon nitride seal which can protect the TBC, allowing increased engine performance and decreased maintenance and replacement costs. Samples of Yttrium Stabilized Zirconia (YSZ) were obtained which were coated with silicon nitride using plasma-enhanced chemical vapor deposition. Transmission Electron Microscopy (TEM) cross sections of the silicon nitride coating before and after annealing show no cracking, delamination, or other degradation at GTE temperatures (800C). With this successful feasibility study in hand, we are encouraged to continue pursuing this technique on larger and more realistic samples in Phase II.