Damage fractography of C/C-SiC composite at elevated temperature under loads

Abstract

Ceramic matrix composites are the promising materials for high temperature application because of their low density, high strength, high toughness and high durability at elevated temperatures. Carbon-carbon-silicon carbide (C/C-SiC) composite is one of the structural materials, which comprises all the above properties at high temperatures. The main objective of present study was to characterize the effects of high temperature in open atmosphere on the stress rupture behaviour of C/C-SiC composite. For this purpose, tensile and compressive stress rupture tests were conducted on oxidized C/C-SiC composites at temperature, 900°C with the variation of exposure time. Finally, Scanning Electron Microscopy (SEM) test was used to evaluate the morphology of fractured and compressed samples. It was a practical and useful way to find out the role of carbon fibre in the strength of carbon fibre reinforced composite. How the strength of composite was going to decrease with the exposure time was also investigated by SEM. Result showed that as the time of exposure increased from 5 min to 20 min the content of carbon going to decrease and microstructure of composite become a porous skeleton of carbon fibres. Copyright © 2008 by JSCM.