Effect of matrix texture on tensile strength and oxidation behavior of carbon fiber reinforced carbon composites

• Published in: Carbon (New York) Vol. 33; no. 4; pp. 405 - 413
• Main Authors: Iwashita, Norio, Sawada, Yoshihiro, Shimizu, Kazuyuki, Shinke, Shigekazu, Shioyama, Hiroshi
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 1995
• Subjects: CC composite; matrix texture; oxidation behavior; tensile strength; wet atmosphere; tensile strength; oxidation behavior; matrix texture; wet atmosphere; CC composite
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/0008-6223(94)00165-V

Unidirectional carbon fiber reinforced carbon composites (CC composites) with different matrix textures were prepared from six matrix precursors. Two composites with an optically isotropic matrix showed tensile strength and modulus values that increased on heat treatment of the samples at a high temperature. Composites with an anisotropic matrix, having preferred orientation parallel to fiber surface, were deformed due to shrinkage as the graphitic structure developed on heat treatment. This caused the fibers to be exfoliated from the anisotropic matrix, as a result of residual stresses generated by restriction of matrix shrinkage. The strengths of the composites with an anisotropic matrix were reduced after graphitization. On oxidation in a wet atmosphere, the composites with an anisotropic matrix showed higher durability than those with isotropic matrices. The oxidation of the former composites was localized at the fibermatrix interphase, but this effect was not observed with isotropic matrix composites.