Chapter 17. Translucent Polycrystalline Ceramic Compacts from Doped Alumina - Sintering Behavior and Microstructure Development

  1. Waltraud M. Kriven and
  2. Hua-Tay Lin
  1. Adelina Braun1,
  2. Matthias Wolff1,
  3. Rolf Clasen1,
  4. Sabine Schlabach2,
  5. Bin Xu2 and
  6. Dieter Vollath2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294826.ch17

27th Annual Cocoa Beach Conference on Advanced Ceramics and Composites: B: Ceramic Engineering and Science Proceedings, Volume 24, Issue 4

27th Annual Cocoa Beach Conference on Advanced Ceramics and Composites: B: Ceramic Engineering and Science Proceedings, Volume 24, Issue 4

How to Cite

Braun, A., Wolff, M., Clasen, R., Schlabach, S., Xu, B. and Vollath, D. (2003) Translucent Polycrystalline Ceramic Compacts from Doped Alumina - Sintering Behavior and Microstructure Development, in 27th Annual Cocoa Beach Conference on Advanced Ceramics and Composites: B: Ceramic Engineering and Science Proceedings, Volume 24, Issue 4 (eds W. M. Kriven and H.-T. Lin), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294826.ch17

Author Information

  1. 1

    Department of Powder Technology Building 43, P. O. Box 15 11 50 Saarland University D-66041 Saarbrücken, Germany

  2. 2

    IMF 111, Research Center Karlsruhe, P.O. Box 3640, D-76021 Karlsruhe, Germany

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 2003

ISBN Information

Print ISBN: 9780470375846

Online ISBN: 9780470294826

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Keywords:

  • polycrystalline;
  • microstructure;
  • ceramics;
  • grain boundaries;
  • metastable nanosized

Summary

Sintered polycrystalline ceramics have complex microstructure that consist of grains, grain boundaries, second phases and pores. An important requirement to achieve transparency is the absence of pores and second phases. Fully dense alumina ceramics cannot be obtained from metastable nanosized Al2O3 powder through conventional sintering, because of the α-phase transformation at temperatures as high as 1200°C, which leads to the so called “vermicular” pore structure. Additives in metastable alumina powder can reduce the transformation temperatures of the α-phase and can prevent grain growth, avoiding the abovementioned structure. To compare the influence of different dopants in alumina is the objective of this work. Two methods of doping were used: liquid-doping technique to introduce the additive into the green body, and gas-phase synthesized powder by microwave plasma reactions to obtain nanosized Al2O3 powder with different dopant contents.