Preferential distribution and oxidation inhibiting/catalytic effects of boron in carbon fiber reinforced carbon (CFRC) composites

✍ Scribed by Young-Jae Lee; Hyeok-Jong Joo; Ljubisa R Radovic

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 369 KB
• Volume: 41
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/s0008-6223(03)00372-5

✦ Synopsis

Two different batches of CFRC composites were prepared in the absence / presence of B with the expectation of increasing oxidation stability and improving the processing compatibility of CFRC composites in commercial applications. The composites were examined to reveal the nature of substitutional B in oxidation, crystallinity and distribution preference in the composites. Substitutional B acts both a catalyst and an inhibitor in carbon oxidation, depending on the content and the extent of carbon burn-off reaction. Crystallinity increases with the incorporation of B, as expected; d decreases, and L 002 c and L increase. Boron prefers to be distributed in the less ordered structure; non-graphitizable PAN-based carbon fibers have a higher B contents than graphitizable coal-tar pitch, but processing conditions can change this preference. The incorporation of B in CFRC composites seems to be beneficial for improving the potential ability of the composites in applications by increasing crystallinity and oxidation stability.