Microstructures and properties of C/C-SiC composites derived from different gaseous carbon matrix precursors

The type of gaseous precursors has a profound influence on the microstructure and properties of carbon fiber based ceramic brake materials. In this work, C/C-SiC composites derived from natural gas (n-C/C-SiC) and propylene (p-C/C-SiC) were prepared by a combined process (chemical vapor infiltration (CVI) and reactive melt infiltration (RMI)), and the microstructure and properties of C/C-SiC composites were investigated. Results indicate that the structure of PyC were a mixed structure with rough surface (rough laminar structure + smooth laminar structure) and smooth laminar structure in n-C/C and p-C/C respectively. And then the rough surface of PyC in n-C/C preform resulted in a smaller crystal size of nano-SiC and mechanisms of liquid silicon infiltration were proposed. Moreover, compared to the p-C/C-SiC composite, the flexural strength and coefficient of friction (COF) of the n-C/C-SiC composite were increased to 208.49(+/- 22.71) MPa and 0.41 respectively and exhibit a relatively stable braking process with lower liner wear rates (LWR).