Chapter 85. High-Temperature Properties of Si3N4/SiC Microcomposites

  1. Todd Jessen and
  2. Ersan Ustundag
  1. Hagen Klemm,
  2. Mathias Herrmann and
  3. Christian Schubert

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294628.ch85

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3

How to Cite

Klemm, H., Herrmann, M. and Schubert, C. (2000) High-Temperature Properties of Si3N4/SiC Microcomposites, in 24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 21, Issue 3 (eds T. Jessen and E. Ustundag), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294628.ch85

Author Information

  1. Fraunhofer-Institute for Ceramic Technologies and Sintered Materials, IKTS Dresden, Winterbergstr. 28, D-01277 Dresden, FRG

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2000

ISBN Information

Print ISBN: 9780470375686

Online ISBN: 9780470294628

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Keywords:

  • microstructure;
  • diesel engines;
  • mechanical properties;
  • intermetallic binder;
  • nickel aluminide

Summary

The influence of nano-or micro-sized SiC additions on the high-temperature behavior of Si3N4 materials was studied. Comparing a Si3N4-SiC composite with a monolithic Si3N4 material with the same chemical composition of the grain boundary phase, no significant effect of the nano-or micro-sized SiC additions on the mechanical properties at elevated temperatures was observed. The main advantage of the Si3N4-SiC composites was found to be the improved oxidation resistance in comparison to the monolithic Si3N4 material. A significantly less degraded microstructure was observed after long-term oxidation of the Si3N4-SiC composites due to an altered oxidation mechanism which promotes the formation of Si2ON2 below the outer oxidation layer in the bulk of the Si3N4-SiC composites. This is also the reason for the improved behavior in terms of time to failure reported in the literature for these Si3N4-SiC composite materials.