Synthesis and characterization of nano-scale and submicro-scale silicon carbide whiskers on C/C composites

- Submicro-scale SiC whiskers were synthesized on C/C composites from H-PSO-DVB precursor with particle size of 100-200 μm.
- Nano-scale SiC whiskers were synthesized on C/C composites from H-PSO-DVB precursor with particle size less than 10 μm.
- High-quality SiC whiskers can be obtained at the preparation temperature of 1500-1600 °C.
- A vapor-vapor mechanism was used to explain the growth process of the SiC whiskers.
- The differences of ATR and Raman spectra between the nano-scale SiC whiskers and bulk SiC were analyzed.

In this paper, a novel synthesis route of nano-scale and submicro-scale silicon carbide (SiC) whiskers on C/C composites was reported. H-PSO-DVB as the organic precursor was used to fabricate the SiC whiskers. The phase, chemical bonds and microstructure of the synthesized whiskers were analyzed in detail. It was shown that C/C composites were packed with a porous network consisting of random-oriented β-SiC whiskers when the preparation temperature is 1500-1600 °C. In view of that most of the SiC whiskers are tip flat or tapering, a vapor-vapor mechanism was used to explain the growth process of the whiskers. The differences of attenuated total reflection (ATR) and Raman spectra between the nano-scale SiC whiskers and bulk SiC were analyzed, which could be reasonably interpreted with the size confinement effect of nanomaterials.