Chapter 60. Tensile Behavior of Sic\Sic Composites Reinforced by Treated Sylramic Sic Fibers

  1. Mrityunjay Singh and
  2. Todd Jessen
  1. H.M. Yun,
  2. J.Z. Gyekenyesi,
  3. Y.L. Chen,
  4. D.R. Wheeler and
  5. J.A. Dicarlo

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294680.ch60

25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3

25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3

How to Cite

Yun, H.M., Gyekenyesi, J.Z., Chen, Y.L., Wheeler, D.R. and Dicarlo, J.A. (2001) Tensile Behavior of Sic\Sic Composites Reinforced by Treated Sylramic Sic Fibers, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 22, Issue 3 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294680.ch60

Author Information

  1. NASA Glenn Research Center, Cleveland, OH 44135

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2001

ISBN Information

Print ISBN: 9780470375730

Online ISBN: 9780470294680

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Keywords:

  • thermomechanical;
  • stoichiometric;
  • composites;
  • fabrication;
  • ceramic

Summary

Near stoichiometric SiC fibers, such as Sylramic and Hi-Nicalon Type S, display very good thermomechanical properties that are essential for high-temperature structural ceramic matrix composites (CMC). Recently NASA has developed a treatment for the Sylramic fiber that further improves its creep-rupture properties and environmental interactions by removing boron from the bulk and forming a thin in-situ BN coating on the fiber surface. To understand its benefits for fiber-controlled CMC properties, this treatment was performed on two-dimensional 0\90 degree woven Sylramic fabric prior to forming SiC\SiC composites with a BN interphase and a melt-infiltration SiC matrix. Tensile stress-strain behavior for the CMC showed a high modulus followed by graceful cracking at a high proportional limit, but more importantly a higher ultimate strength than for the SiC\SiC composites fabricated in the same manner, but reinforced by untreated Sylramic and Hi-Nicalon Type S fibers. It is believed that this improved ultimate strength behavior is primarily related to the in-situ BN coating that acts to protect the fibers from environmental effects introduced during the CMC fabrication process.