Development of Thermal and Environmental Barrier Coatings for SiC/SiC Ceramic Matrix Composite Turbine Engine Components

Ceramic thermal and environmental barrier coatings (T/EBCs) will play a crucial role in advanced turbine engine systems because of their ability to significantly increase engine operating temperatures and reduce cooling requirements, thereby help increase engine efficiency and reduce emission. Under the NASA Fundamental Aeronautics program, advanced T/EBCs along with SiC/SiC ceramic matrix composite (CMC) turbine blade technologies are being developed for next generation supersonics aircraft engines. In this paper, the ceramic CMC coating design and development requirements will be described for supersonics cruise mission applications. Advanced high heat-flux and high pressure burner rig simulated engine testing approaches have also been developed for the coating validation and integration with the CMC components. Multilayered T/EBC coatings consisting of defect-cluster low conductivity oxides, rare earth silicates and alloyed-aluminosilicates have been developed and evaluated for thermal stability, cyclic durability and thermomechanical fatigue resistance in engine relevant environments. The turbine CMC coating systems have demonstrated lower thermal conductivity, improved stability and load capability to meet the design requirements. It is also shown that the coating performance can be further improved by utilizing advanced architecture design and hybrid coating processing, in conjunction with modeling and design tools that are also being pursued in the program.