40. Elevated-Temperature Slow Crack Growth and Room-Temperature Properties of MoSi2-50 vol % Si3N4 Composites

  1. Don Bray
  1. Sung R. Choi1 and
  2. Mohan G. Hebsur2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294482.ch40

22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 19, Issue 3

22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 19, Issue 3

How to Cite

Choi, S. R. and Hebsur, M. G. (1988) Elevated-Temperature Slow Crack Growth and Room-Temperature Properties of MoSi2-50 vol % Si3N4 Composites, in 22nd Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings, Volume 19, Issue 3 (ed D. Bray), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294482.ch40

Author Information

  1. 1

    Cleveland State University, Cleveland, Ohio 44115

  2. 2

    NYMA, NASA Lewis Research Group, Cleveland, Ohio 44135

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1988

ISBN Information

Print ISBN: 9780470375587

Online ISBN: 9780470294482

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Keywords:

  • isostatic;
  • aerospace;
  • voluminous;
  • catastrophic;
  • monolithic

Summary

Two different batches of MoSi2-50 vol % Si3N4 composite were fabricated through hot isostatic pressing. The basic physical and mechanical properties for each batch, such as density, Young's modulus, hardness and fracture toughness, were determined at ambient temperature. The elevated-temperature, slow crack growth of the composite was estimated using constant stressrate testing at 1200°C in air. The first (dense) batch exhibited a moderate slow crack growth (SCG) with a SCG parameter of n = 35. By contrast, the second batch, with a little lower density, exhibited an appreciable SCG with n = 15. The first dense batch also showed better mechanical properties (Young's modulus, hardness and fracture toughness) over the second batch. This indicates that a slight difference in density resulted in a significant difference in SCG behavior as well as in the major mechanical properties of the MoSi2-50 vol% Si3N4 composite.