Microstructure and Properties of Three Phase Carbon and Ceramic Matrix Composites
Sol-Gel technology was used to develop carbon, silicon and oxygen based ceramics as well as their composites with Carbon fiber and nano siliconcarbide as reinforcements. Gels with different composition were prepared from TEOS, HMDSO and DEDMS. Dried gels were post-cured in air and pyrolyzed at 1000oC in nitrogen atmosphere. Each step of sol-gel process was characterized for density, thermal behaviour and functionality. Composites were prepared using different sols (derived from TEOS, HDMSO and DEDMS) as matrix precursors and carbon fabric as reinforcement. To some composites another phase of solid, micro/nano powder precursor of SiC was added to decrease number of impregnation cycles. Latter composites resulted in higher density. Green composites were post-cured and pyrolyzed. These composites were characterized for density and microstructure. It revealed that the resulting matrix was solid glasses and addition of SiC powder facilitated the rapid densification. Composites prepared with SiC nanparticles as well as Carbon fabric as reinforcement exhibit higher flexural strength than those made without nanoparticles. The fracture behaviour is also seen to be of mixed mode failure type.
Takashi Goto, Yi-Bing Cheng and Takashi Akatsu
L. M. Manocha et al., "Microstructure and Properties of Three Phase Carbon and Ceramic Matrix Composites", Key Engineering Materials, Vol. 484, pp. 1-8, 2011