PROGRESS IN EBC DEVELOPMENT FOR SILICON-BASED, NON-OXIDE CERAMICS

摘要

Hydrothermal corrosion is a lifetime-limiting mechanism for silicon-based, non-oxide ceramics in combustion environments. Many desirable materials for use as protective coatings are physically or chemically incompatible with the non-oxide substrate materials. A unique method of engineering bond-coats and coating systems for non-oxide systems has been developed and shown to improve the hydrothermal corrosion resistance of silicon nitride and silicon carbide-based materials. Progress in work to investigate the effect of additions of oxidation resistant filler materials to polymer-derived bond coats for environmental barrier coatings will be discussed. In the current work, additional data will be provided showing that the bond coat system can be adapted to composite silicon carbide. Initial results on the high-temperature durability of these coatings will be presented.