Carbon/carbon (c/c) composites with SiC were prepared by thermal gradient chemical vapor deposition (CVD) technique in order to study the effects of SiC on the microstructure, mechanical properties and fracture behavior.
The various microstructures obtained in this work fall into major types identified as smooth laminar (S·/L), rough laminar (R·L), isotropic, and transition, The variation in microstructure of C/C composites with SiC is different from that of pure C/C composites as the deposition temperature increases. In pure C/C composites, S·L change into transition structure. However, in C/C composites with SiC, isotropic turns into R·L. The microstructural changes in this work are discussed in view of the arragement of planar carbon molecules in deposition layer. The pure C/C composites shows a brittle fracture behavior in all cases. However, in the C/C composites with SiC, fracture behavior changes from brittle-mode to pseudo-plastic mode as deposition temperature increases. The mechanical properties and fracture behavior of C/C composites are influenced by the microstructure which in turn depends on the deposition condition employed.
