Mechanical properties of carbon/carbon composites with the fibre/matrix interface modified by carbon nanofibers

In order to modification, carbon nanofibers (CNFs) are uniformly dispersed on the fiber surface of the unidirectional carbon preform. The modified unidirectional carbon preform was then densified to obtain CNF-C/C composite by chemical vapor deposition (CVD). The microstructure and mechanical properties of the CNF-C/C composite were investigated. Results show that CNFs on carbon fibers become the active points and induce the ordered deposition of PyC during CVD. In the CNF-C/C composite, there is an interface layer composed of CNFs and high texture PyC around them between the fibers and matrix. After the modification of fiber/matrix interface by CNFs, the mechanical properties of C/C composite are adjusted. After modification, the fracture mode is changed and the flexural strength is enhanced in both vertical and parallel direction.