Chapter 24. Sintering of Amorphous Mullite with Crystalline Inclusions
- John B. Wachtman Jr
Published Online: 28 MAR 2008
Copyright © 1991 The American Ceramic Society, Inc.
Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 7/8
How to Cite
Jeng, D.-Y. and Rahaman, M. N. (2008) Sintering of Amorphous Mullite with Crystalline Inclusions, in Proceedings of the 15th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 12, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470313831.ch24
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1991
Print ISBN: 9780470375099
Online ISBN: 9780470313831
Highly sinterable amorphous mullite powder with the stoichiometric composition (3Al2O3·2SiO2) was synthesized by a sol-gel route and used as the matrix phase in the formation of particulate composites by conventional, pressureless sintering. The compacted mullite powder sintered to nearly theoretical density below ≈1200°C and the X-ray diffraction pattern of the fully crystallized powder was almost identical to that of stoichiometric mullite. The effect of rigid, crystalline mullite or ZrO2 inclusions on the sinterability of the synthesized mullite powder was investigated. Composites containing up to 22.5 vol% ZrO2 sintered to almost full density. However, the sintered density of the composites containing mullite inclusions decreased with either increasing volume fraction or decreasing size of the inclusions. While no reaction occurred between the ZrO2 inclusions and the matrix, X-ray data indicated that the mullite inclusions enhanced the independent nucleation and growth rate of the mullite crystals in the matrix.