Chapter 33. High Temperature Mechanical Properties of SiAlON Ceramics: Microstructural Effects

  1. William Smothers
  1. Ching-Fong Chen and
  2. Tseng-Ying Tien

Published Online: 26 MAR 2008

DOI: 10.1002/9780470320402.ch33

11th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 8, Issue 7/8

11th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 8, Issue 7/8

How to Cite

Chen, C.-F. and Tien, T.-Y. (1987) High Temperature Mechanical Properties of SiAlON Ceramics: Microstructural Effects, in 11th Annual Conference on Composites and Advanced Ceramic Materials: Ceramic Engineering and Science Proceedings, Volume 8, Issue 7/8 (ed W. Smothers), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470320402.ch33

Author Information

  1. Dept. of Materials Sci. and Eng. Univ. of Michigan Ann Arbor, MI 48109

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1987

ISBN Information

Print ISBN: 9780470374733

Online ISBN: 9780470320402

SEARCH

Keywords:

  • mechanism;
  • multigrain;
  • intergranular;
  • SiAlON;
  • crystallization

Summary

Tensile creep of both as-hot-pressed and annealed SiAlON-YAG ceramics has been identified as creep damage (cavitation and cavity growth) the mechanism dominating the creep life. The hot-pressed sample has β-SiAlON grain as the only crystalline phase surrounded by a vitreous matrix. When this material sustains creep, cavities nucleate within the multigrain junctions and the majority of cavities are followed by viscous flow growth. However, the annealed sample has β-SiAlON grain surrounded by crystalline YAG. When this material sustains creep, cavities nucleate at the interphase of SiAlON and YAG phases and the majority of cavities are followed by diffusive crack growth. Creep curves and TEM post-crept investigation shows that crystallizing the grain boundary vitreous phase can increase the creep life by reducing cavitation rate and cavity growth rate. Also, increasing the hot-pressing time can affect the creep behaviors by reducing the number of multigrain junctions, thus, decrease cavitation rate.