45. Potential Use of Mullite-SiC Whiskers-SiC Particles Multi-Composite as High Temperature Springs

  1. Edgar Lara-Curzio
  1. Wataru Nakao1,
  2. Koji Takahashi1,
  3. Kotoji Ando1 and
  4. Masahiro Yokouchi2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470291221.ch45

Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2

Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2

How to Cite

Nakao, W., Takahashi, K., Ando, K. and Yokouchi, M. (2005) Potential Use of Mullite-SiC Whiskers-SiC Particles Multi-Composite as High Temperature Springs, in Mechanical Properties and Performance of Engineering Ceramics and Composites: Ceramic Engineering and Science Proceedings, Volume 26, Number 2 (ed E. Lara-Curzio), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470291221.ch45

Author Information

  1. 1

    Yokohama National University 79-5, Tokiwadai, Hodogaya-ku Yokohama, Kanagawa, 240-8501

  2. 2

    Kanagawa Industrial Technology Research Institute 705-1 Imaizumi, Ebina, Kanagawa, 243-0435

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2005

ISBN Information

Print ISBN: 9781574982329

Online ISBN: 9780470291221

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Keywords:

  • ceramics springs;
  • young's modulus;
  • sic whiskers;
  • crack-healing treatment;
  • mullite powder

Summary

Mullite has high fracture strength at high temperature, excellent resistance to heat, corrosion and oxidation as well as low Young's modulus. Thus, mullite is well suited for cushions and springs used at high temperatures. However, the low fracture toughness and reliability of mullite prevents use in these applications. If the reliability of mullite is improved through self-crack-healing ability, the use of mullite would be possible in these applications. In this study, mullite/SiC particle/SiC whisker multi-composites with improved fracture toughness and excellent self-crack-healing ability where the crack-healed part is stronger than the base materials were developed. Fracture strength and Young's modulus of mullite/15 vol% SiC whiskers/10 vol% SiC particles multi-composite were found to be 750 MPa and 272 GPa, respectively. The maximum strain of the composite was evaluated to be 0.79 %. The value is almost 2 times larger than the monolithic mullite. The mullite multi-composite has 2.2 times larger fracture toughness of monolithic mullite. Moreover, mullite/15 vol% SiC whiskers/10 vol% SiC particles multi-composite can completely heal a pre-crack of 100 m̈m in surface length by exposure for 2 h in air at 1573 K. The crack-healed part was also found to be stronger than the base materials up to 1573 K.