Abstract
The structure, crystallinity and preferred orientation of the SiC coated on carbon fiber at 1200°C from mixtures of monomethyltrichlorosilane, hydrogen, methane and argon were studied by X-ray and selected area electron diffractometries. The SiC was identified to be 3C type, in which the stacking sequence of the closest packed layers is highly disordered along one of the [111] directions. Moreover, it was found that a decrease in hydrogen concentration or an increase in methane concentration enhances the orientation of these layers parallel to the fiber surface, and increases the crystallite size. Such changes in the orientation and the crystallite size are considered to be due to the increase in methane concentration in the reaction zone.
