Growth of carbon nanotubes on silicon carbide fabric as reinforcement for SiC/C composites.

Carbon nanotubes (CNTs) have been grown on conventional silicon carbide (SiC) fabric by the catalytic chemical vapour deposition (CCVD) technique. These hybrid reinforcements have been used to develop Silicon carbide-carbon nanotube-carbon matrix mini-composites (SiC/CNTs/C) by chemical vapour infiltration (CVI) method. The microstructures of these hybrid materials and their composites have been studied using scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscope. The microstructure of the carbon matrix has been compared with the silicon carbide-carbon matrix composites (SiC/C) made with SiC fabric alone. It has been found that the carbon matrix exhibit orientation circumferentially around the SiC fibers. In case of composites with CNTs coated SiC fibers, the carbon matrix is found to get infiltrated within the bundles of CNTs whereas at distance away from the CNTs, the matrix is found to be oriented circumferentially around the SiC/CNT bundles. SiC/CNT/C composites are found to exhibit inherent intrabundle porosity and lower density.