Preparation and mechanical behaviors of multiscale SiC nanowires/carbon fiber reinforced silicon oxycarbide ceramic composites

3D-carbon fiber felts reinforced ceramic-based composites are considered as valuable structural materials due to their excellent high-temperature mechanical performance, low density and low thermal conductivity. In order to enhance the mechanical properties of the carbon fiber reinforced silicon oxycarbide (SiOC) ceramics, in-situ growth of SiCnws on the surface of carbon fiber via a simple precursor impregnation and pyrolysis method was proposed. As a result, nanoscale SiC nanowires and microscale carbon fiber felts reinforced SiOC ceramics were successfully fabricated. The results showed that the compressive strength of the composite increased by 369% and 173% after two PIP process in x/y and z directions, respectively. The enhanced compressive strength could be ascribed to the brittle fracture of SiCnws and CFs, and crack deflection.

Automated summary

3D-carbon fiber felts reinforced ceramic-based composites have excellent high-temperature mechanical performance, low density, and low thermal conductivity. By in-situ growing SiC nanowires on the surface of carbon fiber, the compressive strength of the composite was significantly enhanced by the brittle fracture of SiC nanowires and carbon fibers, as well as crack deflection.