Effect of Additional Particulate Reinforcement on the Properties of Fibrous Ceramic Matrix Composites

Abstract

Composites, generally, consist of two phase i.e. matrix and reinforcement. Here in this work additional phase in terms of micro/nano particles was added in the fiber reinforced ceramic matrix composites and its effect on the final properties of composites was studied. Composites were prepared using sol derived from Tetraethoxysilane (TEOS) and Dimethyldiethoxysilane (DEDMS), and polycarbosilane (PCS) as matrix precursors and SiC 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. Some of the composites were heated to 1500 °C in argon atmosphere. Composites were characterized for density, microstructure and mechanical properties. It revealed that the resulting matrix was solid glass and addition of SiC powder facilitated the rapid densification. Composites prepared with SiC nanoparticles as well as SiC 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.