Kinetic studies on β-SiC formation from homogeneous precursors

The kinetics of the carbothermic reduction of SiO2 by carbon to produce beta-SiC from a homogeneous organic precursor has been investigated over the temperature range 1500 to 1800 C in nitrogen by the use of a high- temperature thermobalance. The kinetic behavior differed significantly from that of...

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Bibliographic Details
Published in:Journal of materials science 1991-01, Vol.26 (2), p.388-392
Main Authors: ONO, K, KURACHI, Y
Format: Article
Language:English
Subjects:
Applied sciences
Building materials. Ceramics. Glasses
Ceramic industries
Chemical industry and chemicals
Exact sciences and technology
Structural ceramics
Technical ceramics
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Summary:The kinetics of the carbothermic reduction of SiO2 by carbon to produce beta-SiC from a homogeneous organic precursor has been investigated over the temperature range 1500 to 1800 C in nitrogen by the use of a high- temperature thermobalance. The kinetic behavior differed significantly from that of the heterogeneous reaction of SiO2 and carbon particles. The weight-loss curves could be fitted well by the Avrami-Erofe'ev equation with an exponent of 1.5. The result was interpreted as showing instantaneous nucleation in a homogeneous matrix followed by the diffusion- controlled growth of beta-SiC. The obtained activation energy of 391 kJ/mol was consistent with the assumption that the reaction is controlled by the diffusion of carbon through the amorphous matrix to the growing surface of beta-SiC. (Author)
ISSN:0022-2461
1573-4803
DOI:10.1007/BF00576531