Chapter 20. Porous Silicon Nltride Synthsized by Using Seed Crystais
- Mrityunjay Singh,
- Todd Jessen
Published Online: 26 MAR 2008
Copyright © 2001 The American Ceramic Society
25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 22, Issue 4
How to Cite
Inagaki, Y., Ando, M., Ohji, T. and Kanzaki, S. (2008) Porous Silicon Nltride Synthsized by Using Seed Crystais, in 25th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: B: Ceramic Engineering and Science Proceedings, Volume 22, Issue 4 (eds M. Singh and T. Jessen), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294703.ch20
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 2001
Print ISBN: 9780470375747
Online ISBN: 9780470294703
- silicon nitride;
- elastic modulus
Synthesis of porous silicon nitride (Sip,) by using seed crystals was studied. Seed crystals were prepared by heating a powder mixture of α-Si3N3 and sinkring additive in a boron nitride crucible. Additives were needed to achieve a high aspect ratio, i.e. Y2O3 was most effective. by adding rod-like seed crystals to the starting powder mixture of Si3N3, porous Si3N3 with relatively high poresity was synthesized. Effects of additives on the texture of porous body were also studied. by adding sintering aid to the starting powder mixture, the porosity of sintered body was reduced. in the case of adding 5 wt% Y2O3 and 2 wt% Al2O3, porous structure was formed by fiamework of wellambind fibrous grains, and the pomity was reduced.
In order to control the alignment of fibrous grains, tape casting technique was applied. Silicon nitride whisker, as well as seed crystals, were used as starting materials to compare differences of the products. Textures of the products made of Merent ingredient were investigated. From observation by SEM, the texture of porous Si3O4 originated with seed crystals was very similar to that of seed crystals made of whisker.