Effect of fiber characteristics on fracture behavior of
Cf/SiC composites
Cf/SiC composites
(1. Department of Materials Science and Engineering,
Zhejiang University, Hangzhou 310027, China；
2. Department of Materials Science and Engineering,
Central South University, Changsha 410083, China)
Zhejiang University, Hangzhou 310027, China；
2. Department of Materials Science and Engineering,
Central South University, Changsha 410083, China)
Abstract: Cf/SiC composites were prepared by precursor pyrolysis-hot pressing, and the effect of fiber characteristics on the fracture behavior of the composites was investigated. Because the heat treatment temperature of fiber T300 (below 1500 ℃) was much lower than that of fiber M40JB (over 2000℃), fiber T300 had lower degree of graphitization and consisted of more impurities compared with fiber M40JB, suggesting that T300 exhibits higher chemical activity. As a result, the composite with T300 showed a brittle fracture behavior, which is mainly ascribed to a strongly bonded fiber/matrix interface as well as the degradation of fibers during the preparation of the composite. However, the composite wit h M40JB exhibits a tough fracture behavior, which is primarily attributed to aweakly bonded fiber/matrix interface and higher strength retention of the fibers.
Key words: Cf/SiC composites; fiber characteristics; fracture behavior