Chapter 25. Polymer Derived Nicalon/Si-C-O Composites: Processing and Mechanical Behavior
- John B. Wachtman Jr.
Published Online: 26 MAR 2008
Copyright © 1989 The American Ceramic Society, Inc.
A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8
How to Cite
Hurwitz, F. I., Gyekenyesi, J. Z. and Conroy, P. J. (1989) Polymer Derived Nicalon/Si-C-O Composites: Processing and Mechanical Behavior, in A Collection of Papers Presented at the 13th Annual Conference on Composites and Advanced Ceramic Materials, Part 1 of 2: Ceramic Engineering and Science Proceedings, Volume 10, Issue 7/8 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470310557.ch25
- Published Online: 26 MAR 2008
- Published Print: 1 JAN 1989
Print ISBN: 9780470374863
Online ISBN: 9780470310557
- chemical vapor infiltration;
- fiber-matrix reactions;
- polysilsesquioxane system;
- thermogravimetric analysis
Ceramic matrix composites fabricated using Nicalon fiber and several pofysilsesqui-oxane-derived Si-C-O matrices were characterized by optical and scanning electron microscopy and in four-point bending. Material variables include three Nicalon sizings, poly(vinylacetate), epoxy and DCC-1, two different copofymer compositions, and several pyrolysis schedules. Shrinkage of the matrix during pyrofysis results in a 65% char yield on heating to 1500°C for both the pofyvinylmethylsils-esquioxane and polyphenylmethylsilsesquioxane copofymers studied. In the matrix material linear shrinkages of up to 19% were observed for the vinylmethyl copofymer pyrolyzed to 1200°C, and up to 13% for the phenylmethyl material pyrolyzed to the same temperature, resulting in considerable matrix cracking. Under four-point loading, most composite samples fractured in a brittle manner as the result of strong fiber-matrix bonding. Flexural strengths, moduli, and ultimate strain varied with fiber sizing and processing parameters. Testing and analysis is being applied to promote more fibrous pullout during fracture.