TRANSPARENT CHEMICAL-VAPOR-DEPOSITED BETA-SIC

Transparent beta-SiC has been fabricated by the pyrolysis of methyltrichlorosilane in a hot wall chemical vapor deposition reactor. Characterization of material indicates that transparent SiC is ct theoretically dense, highly pure (99.9996%), highly oriented (111), beta-phase (cubic) material possessing high optical transmission in the wavelength region 0.5-6 mu m, a high value of hardness, electrical resistivity and thermal conductivity, and a low value of thermal expansion coefficient. These properties make it a good candidate material for use as domes and windows in severe environments such as high speed missiles, laser, combustion and space systems.