Theoretical design and preparation of SiC whiskers catalyzed by Fe-oxides on carbon fibers

This work reported an in-situ vapor-liquid-solid (VLS) preparation method of SiC whiskers (SiCw) catalyzed by Fe-oxides on carbon fibers, which could provide a method for preparing SiCw/carbon fiber composites. The mechanism of the SiCw was theoretically designed and then experimentally validated using XRD, SEM, and TEM. Fe2O3 was chosen as a Fe-oxide catalyst and directly loaded on carbon fibers by the impregnation process. The results showed that SiCw were successfully prepared on carbon fibers at 1600 °C under the protection of flowing nitrogen, utilizing quartz and graphite as gas-phase generation sources. The prepared SiCw were β-SiC and grew along the (111) crystal plane, with spherical droplets on top formed by Fe2O3 catalysts. SiCw were microstructurally observed to have widths of 500–1000 nm and lengths of more than 15 μm, respectively.