Chapter 59. Creep Resistance of Nextel™ 312/BN/Blackglas™ Composites

  1. John B. Wachtman Jr
  1. K. Ranji Vaidyanalhan1,
  2. W. Roger Cannon1,
  3. Stephen C. Danforth1 and
  4. Albert G. Tobin2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470314715.ch59

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4

How to Cite

Vaidyanalhan, K. R., Cannon, W. R., Danforth, S. C. and Tobin, A. G. (1995) Creep Resistance of Nextel™ 312/BN/Blackglas™ Composites, in Proceedings of the 19th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 16, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314715.ch59

Author Information

  1. 1

    Center for Ceramic Research, Rutgers University, Piscataway, NJ 08855-0909

  2. 2

    Grumman Aerospace & Electronics R&D Center, Bethpage, NY 11714

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1995

ISBN Information

Print ISBN: 9780470375372

Online ISBN: 9780470314715

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Keywords:

  • creep;
  • oxidation;
  • fiber;
  • ceramic;
  • fabricated

Summary

Ceramic matrix composites based on a Blackglas™ matrix reinforced with Nextel™ 312 fibers with a BN rich surface layer are being investigated for gas turbine engine applications in a temperature range of 500–600°C. Previous work has shown that the flexural properties of the Nextel™ 312/BN/Blackglas™ composites improved after exposure to flowing air at 600°C up to 100h. The creep properties of pre-oxidized specimens (600°C for 100h) were investigated at 566°C. The stress levels were varied between 25-67 MPa. The temperature and stress levels were selected based on the actual component requirements. The creep curve exhibited a large primary region and a flat steady state region with an overall creep rate of approximately 10−10 s1 over 750 hours. The primary region is believed to be due to a) fibers straightening out, and b) load shifting to the fibers due to the effects of oxidation on the matrix. The total creep strains were observed to be about 0.25% after exposure to creep stresses for 850h, which is less than the maximum allowable design strain limits for the component. The creep failure stress of 67 MPa over 750 hours is lower than the fracture strength at temperature.