Porous SiC Ceramics Obtained by SHS (Self Propagating High Temperature Synthesis)

Porous SiC ceramics have been prepared by two different routes which both involve an SHS step. The first one, consists of heating a Si+C mixture up to 1400 deg C and maintaining it at this temperature for a duration between 10 min. and 1h. For the second process, the complete reaction is obtained, a...

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Bibliographic Details
Published in:Key Engineering Materials 2002-01, Vol.206-213 (3), p.1973-1976
Main Authors: Morançais, Aurore, Smith, David S., Louvet, F., Bonnet, Jean Pierre
Format: Article
Language:English
Online Access:Get full text
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Summary:Porous SiC ceramics have been prepared by two different routes which both involve an SHS step. The first one, consists of heating a Si+C mixture up to 1400 deg C and maintaining it at this temperature for a duration between 10 min. and 1h. For the second process, the complete reaction is obtained, after heating up to 1430 deg C, by driving a weak electric current through the sample for a few seconds. Both processes lead to SiC ceramics with very high porosity (75-80%). The size of the pores is strongly dependent on the process. Larger pores are obtained with the method using the electric current. A link seems to exist between the amount of liquid silicon formed during the process and the pore size. Depending on the process, the graphite morphology and the silicon grain size, it is possible to prepare porous SiC ceramics with an average pore size ranging from 0.3 to 20 mu m.
ISSN:1013-9826
1662-9795
1662-9795
DOI:10.4028/www.scientific.net/KEM.206-213.1973