Chapter 16. Sintering and Creep Behavior of SiO2/Si3N4 Compacts Prepared from Microcomposite Particles

  1. John B. Wachtman Jr.
  1. Ramesh Raghunathan and
  2. Michael D. Sacks

Published Online: 26 MAR 2008

DOI: 10.1002/9780470314821.ch16

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 17, Issue 3

Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 17, Issue 3

How to Cite

Raghunathan, R. and Sacks, M. D. (1996) Sintering and Creep Behavior of SiO2/Si3N4 Compacts Prepared from Microcomposite Particles, in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - A: Ceramic Engineering and Science Proceedings, Volume 17, Issue 3 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314821.ch16

Author Information

  1. Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611.

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1996

ISBN Information

Print ISBN: 9780470375426

Online ISBN: 9780470314821

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Keywords:

  • submicrometer;
  • densification;
  • sintering;
  • concentration;
  • elevated

Summary

SiO2/Si3N4 composites were fabricated using submicrometer composite particles which consisted of inner cores of Si3N4 and outer coatings of amorphous SiO2 Powder compacts prepared with these “microcomposite” particles showed enhanced densification compared to compacts prepared from a mixture of SiO2 and Si3N4 powders. Electron microscopy observations on sintered composites indicated that densification of the mixed powder samples was constrained by the development of rigid networks of the “non-sinterable” Si3N4 particles. In contrast, the controlled spatial distribution of phases (core + coating) in the microcomposite particles inhibited the formation of Si3N4 particle-particle contacts during sintering. Compacts with 40 vol% Si3N4 were sintered to full density (is., zero porosity) at temperatures ⩽ 1300°C. The low sintering temperature was attributed to densification by viscous flow of the SiO2 coatings. This was consistent with the deformation mechanism determined in compressive creep experiments on dense composite samples.