Synthesis of Silicon Carbide Whiskers From CoconutFibres and Sol-Gel Derived Silica

摘要

Silicon carbide whiskers (SiC SiCw), which areemployed in the development of ceramic matrixcomposites (CMC) and metal matrix composites(MMC) due to their superior mechanical and thermalproperties, are synthesised through chemical vaporinfiltration (CVI) and carbothermal reduction of silica.Synthesis of SiC), SiCw from rice husk which contains silicaand carbon precursor in its structure is widely reported.The present investigation reports the synthesis of SiCSiCwfrom coconut fibres through sol-gel process. Thecoconut fibres, which contain around 30% of carbonwere impregnated with the sol derived by hydrolysingtetraethoxysilane (TEOS), methyltriethoxysilane(MTEOS) and dimethyldiethoxysilane (DMDEOS)and pyrolyzed at 1400 °C in an argon atmosphere. Xraypowder patterns of the pyrolyzed samples showedthe formation of β-SiC. SiCSiCw were seen when thesamples were examined under SEM. The methylgroup attached to silicon atom in the silicon alkoxidesprobably helps in the formation of the silicon carbidewhiskers.