Abstract
Carbon fiber/Carbon composite (C/C) was coated with borosiloxane (PBS), an organometallic compound, and heat-treated to form an oxidation preventing film, with the aim of improving the oxidation resistivity. Coating of PBS on C/C was studied by two ways, immersion method and PBS melting method. Oxidation resistivity of C/C coated with PBS was evaluated by measuring the starting temperature of weight loss in thermogravimetric analysis. Of these two methods, PBS melting marked greater improvement of oxidation resistivity.
For the C/C coated by PBS melting, starting temperature of weight loss shifted upward by 200°C. After the thermogravimetric analysis up to 1000°C, it was recognized that C/C had partly remained without burning completely. Oxidation resistivity of PBS-coated C/C was also examined by SEM observation of the sample after its thermal analysis, and by X-ray diffractometry of the film.
The reason for improving the oxidation resistivity of C/C by PBS coating is considered because of the following two points.(1) Oxidation resisting film was formed on the surface of C/C.(2) Diffusion of silicon take place on the interface between C/C and PBS, which caused the ceramification of C/C itself.
