SiC material produced by carbothermal reduction of a freeze gel silica-carbon artefact

• Published in: Journal of the European Ceramic Society 1999-01, Vol.19 (4), p.427-432
• Main Authors: Vix-Guterl, C., McEnaney, B., Ehrburger, P.
• Format: Article
• Language: English
• Subjects: Applied sciences; Building materials. Ceramics. Glasses; carbon; carbothermal reduction; Ceramic industries; Chemical industry and chemicals; Exact sciences and technology; Miscellaneous; SiC; SiO 2; sol–gel process; Technical ceramics
• ISSN: 0955-2219; 1873-619X
• DOI: 10.1016/S0955-2219(98)00223-4

A carbon–silica artefact was produced by infiltration of phenolic resin into the macroporous texture of a silica sample followed by subsequent carbonisation. The silica material was manufactured using an original sol–gel method. This work reports on the conversion into SiC of the silica–carbon artefact heat-treated up to 1550 °C under different gaseous environments. The extent of the carbothermal reduction was followed by thermogravimetric analysis, X-ray diffraction, gas adsorption and scanning electron microscopy. Experiment results demonstrate that a β-SiC artefact with a shape similar to the starting material is obtained by heat treatment of the carbon-silica artefact above 1470 °C. Quantitative formation of SiC is observed by lowering the partial pressure of CO in the reactor. Moreover, the as-obtained SiC material exhibits a granular aspect associated with a significant specific surface area. In a more general way, the procedure described in this work to obtain the SiC material may be a promising route for designing ceramic materials with specific properties.