Refractory Oxide Coatings on Sic Ceramics

Silicon carbide with a refractory oxide coating is potentially a very attractive ceramic system. It offers the desirable mechanical and physical properties of SiC and the environmental durability of a refractory oxide. The development of a thermal shock resistant plasma-sprayed mullite coating on SiC is discussed. The durability of the mullite/SiC in oxidizing, reducing, and molten salt environments is discussed. In general, this system exhibits better behavior than uncoated SiC. Areas for further developments are discussed.