Chapter 29. Interface Modification During Oxidation of a Glass-Ceramic Matrix / SiC Fibre Composite.
- John B. Wachtman Jr.
Published Online: 28 MAR 2008
Copyright © 1996 The American Ceramic Society
Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4
How to Cite
Daniel, A. M., Martin-Meizoso, A., Plucknett, K. P. and Braski, D. N. (1996) Interface Modification During Oxidation of a Glass-Ceramic Matrix / SiC Fibre Composite., in Proceedings of the 20th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures - B: Ceramic Engineering and Science Proceedings, Volume 17, Issue 4 (ed J. B. Wachtman), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470314876.ch29
- Published Online: 28 MAR 2008
- Published Print: 1 JAN 1996
Print ISBN: 9780470375433
Online ISBN: 9780470314876
- oxidation heat treatments;
- calcium aluminosilicate glass-ceramic matrix;
- nano-indentation system;
- fibre push-down tests;
- fracture surface energy
Oxidation heat treatments between 375°C and 600°C for 100 hours in air, have been performed on the calcium aluminosilicate glass-ceramic matrix / SiC fibre reinforced composite CAS/Nicalon (manufactured by Corning, USA). Using a commercial nano-indentation system to perform fibre push-down tests, the fibre-matrix interfacial debond fracture surface energy (Gi) and frictional shear stress (τ) have been determined. Modification of interface properties, compared to the as-fabricated material, was observed at heat treatment temperatures as low as 375°C, where a significant drop in Gi and an increase in τ were recorded. With 450°C, 525°C and 600°C heat treatments, an increase in Gi but a dramatic increase in t were recorded. Under four-point flexure testing, the as fabricated and the 375°C heat treated materials displayed tough, composite behaviour with extensive fibre pull out, but at ≥ 450°C, brittle failure with minimal fibre pull out, was observed. This transition from tough mechanical response to one of brittleness is due to the large increase in τ reducing fibre pull out to a minimum and therefore reducing the total required work of fracture. The large increases in τ and Gi have been attributed to the oxidative removal of the lubricating, carbon interface and the compressive residual stresses across the interface.