Chapter 15. Advanced Packing Theory Predicts Super Ceramic Composites
- 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
Milewski, J. V. (1991) Advanced Packing Theory Predicts Super Ceramic Composites, 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.ch15
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1991
Print ISBN: 9780470375099
Online ISBN: 9780470313831
All currently made whisker composites fall short of their theoretical potential. This shortfall can be related to poor packing of fibers and ceramic powder combinations. This is a direct result of the quality of the whiskers that are being made today. All currently available whiskers are made by processes that produce fibers with a wide range of diameters and length. This produces a short fiber product with a broad range of aspect ratios. This gives a user a product with about 10% of the fibers too short and 30% too long. The fibers that are too short take away strength while the fibers that are too long make processing difficult, especially mixing and uniform distribution. Also, many of the longer fibers remain balled up in clusters or clumps and do not contribute to the reinforcing and make full densification difficult. Packing theory points the way to overcome these problems and it predicts that with a larger diameter and more uniform aspect ratio whiskers, the compounder will have a more uniform dispersion, easier processing, permit higher loadings, and get superior properties. This paper explains the details of advanced packing theory and how it leads to these conclusions and predictions.