抄録
Carbon fiber reinforced carbon composites (C/C composites) are fabricated from PAN- and pitch-based carbon fibers. The carbon matrix of the composites is prepared from phenol resin. In addition to this, the pitch matrix precursor is re-impregnated by HIP into the carbonized composite. Finally, the re-impregnated composites are graphitzed. The mechanical property of the composites is then evaluated using a 4-point bending test at ambient temperature, 2000°C and 2200°C. The morphology of the C/C composites following the bending test at different temperatures is observed under OM and SEM. The bending strength of C/C composites at 2000°C is ca. 1.5 times higher than that at ambient temperature, being independent of type of carbon fiber. The composite from PAN-based composites shows a lower modulus with the elevated test temperature from 2000°C to 2200°C. On the other hand, the modulus of the composites from pitch-based carbon fiber shows almost no change at high temperatures. For the C/C Composite from pitch-based carbon fiber, it is observed that some buckling fractures of carbon fiber tows and plastic deformation of the carbon fibers is observed after the bending test above 2000°C. However, such fractures and deformation are rarely almost observed in the composite from PAN-based carbon fiber.
