Chapter 98. A Reaction-Bonding Method for Sintered SiC Without Residual Silicon

  1. Hua-Tay Lin and
  2. Mrityunjay Singh
  1. John P. Kay and
  2. John P. Hurley

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294741.ch98

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3

How to Cite

Kay, J. P. and Hurley, J. P. (2008) A Reaction-Bonding Method for Sintered SiC Without Residual Silicon, in 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 23, Issue 3 (eds H.-T. Lin and M. Singh), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294741.ch98

Author Information

  1. Energy & Environmental Research Center PO Box 9018 Grand Forks, ND 58202–9018

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2002

ISBN Information

Print ISBN: 9780470375785

Online ISBN: 9780470294741

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Keywords:

  • unreacted compounds;
  • high-carbon-yield resin;
  • carbon-infiltrated;
  • reaction-bonding

Summary

A method for joining sintered silicon carbide (SiC) is being developed at the University of North Dakota Energy & Environmental Research Center. The key to developing a successful technique will be the use of Joule heating and reactive joining compounds to lower the joining temperature without leaving continuous channels of unreacted compounds that can weaken the joint at temperature or serve as conduits for the transport of corrodents. Earlier tests were performed with a joining compound composed of silicon, carbon, and SiC powders pressed and placed between two SiC bars. Electric current is passed through the joint to heat it. Although this technique has produced joints, strengths were only 20 to 30 MPa in four-point flexure. The weakness was due to porosities as high as 50% and incomplete reaction between the silicon and carbon. To decrease porosity, methods to densify the green reaction-bonding compact and increase interaction between the reacting materials are being investigated. One of the reacting materials must flow to fill the interstices between the particles of the other reactant and the SiC filler particles. However, to prevent the formation of continuous channels of unreacted material in the joint, the use of reactant flow during the preparation of the compact, not during the reaction to form SiC in the joint, is being tested. In addition, to increase the bonding with the filler SiC particles, a method has been developed to coat them with one of the reactants. SiC filler particles are coated with silicon, and carbon is made to flow into the interstices by infiltrating with a high-carbon-yield resin. The carbon-infiltrated silicon-SiC preform is reacted to make the joint, possibly followed by densification by infiltration with a preceramic polymer and refiring. Beyond using the carbon-infiltrated silicon-SiC composite for joining sintered SiC, this procedure can produce relatively low-cost SiCp-SiC composite structures from the reaction-bonding material. Strength testing of the joints and composites has not yet been performed.