Abstract
The pyrolytic process of amorphous Si-Ti-C-O fiber (Tyranno) containing 17.8mass%0 was investigated in argon and oxygen atomospheres at temperatures from 1473 to 1673K. The amorphous fiber crystallizes rapidly to β-SiC and TiC by the pyrolysis in an argon atomosphere. By this pyrolysis, the mechanical properties of the fiber deteriorate remarkably at temperatures above 1573K. On the other hand, the dense oxide film consisted of cristobalite and rutile was formed on the surface of the fiber by the oxidation, which suppresses the pyrolysis in the inner area of the fiber. After the oxide film was formed on the surface of the fiber in an oxygen atomosphere at 1673K, therefore, the pyrolysis of the fiber decreased significantly in an argon atomosphere. Finally, thermal-resistant characteristics of the fiber were found to be improved by the form of the oxide film.
