Chapter 55. Microstructure Control of Alumina Ceramics

  1. Todd Jessen and
  2. Ersan Ustundag
  1. Satoshi Iio,
  2. Hiroshi Yamamoto and
  3. Takeshi Mitsuoka

Published Online: 28 MAR 2008

DOI: 10.1002/9780470294635.ch55

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 21, Issue 4

24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 21, Issue 4

How to Cite

Iio, S., Yamamoto, H. and Mitsuoka, T. (2000) Microstructure Control of Alumina Ceramics, in 24th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 21, Issue 4 (eds T. Jessen and E. Ustundag), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294635.ch55

Author Information

  1. R & D Center NGK Spark Plug Co., Ltd. 2808, Iwasaki, Komaki-shi Aichi 485–8510, Japan

Publication History

  1. Published Online: 28 MAR 2008
  2. Published Print: 1 JAN 2000

ISBN Information

Print ISBN: 9780470375693

Online ISBN: 9780470294635

SEARCH

Keywords:

  • microstructure control;
  • alumina ceramics;
  • elevated temperatures;
  • high corrosion resistance;
  • alumina matrix

Summary

Microstructure control of alumina ceramics by addition of small amounts of sintering additives was studied with emphasis on improvement of mechanical properties. In situ formation of platelet-like grains occurred during sintering by adding oxides in combination such as SiO2-Nb2O5 and TiO2-Co2O2. Flexural strength and fracture toughness were remarkably improved simultaneously by optimizing the microstructure as compared with those of the conventional alumina ceramics having equiaxial grains. The toughening mechanism is thought to be the combined effect of crack deflection and grain bridging, being promoted by the change of the microstructure from equiaxial to platelet-like grains. This also affected the thermal shock resistance, flexural strength at elevated temperatures, and cyclic fatigue behavior.