A comparative study on Cf/PyC/SiC minicomposites prepared via CVI process for hypersonic engine application

Carbon fiber reinforced silicon carbide (SiC) minicomposites were prepared from three variants of commercially available carbon fibers, viz., T300-3K, T300J-3K, and T300-6K. The SiC matrix infiltration was done via chemical vapor infiltration process using methyltrichlorosilane as the precursor. Minicomposites were characterized for the composition and morphology of the matrix material deposited. It was found that the matrix contains 2H-SiC along with the major phase 3C-SiC. Cyclic tensile tests were carried out on the composites to understand the damage mechanism and load bearing characteristics under cyclic loading conditions. The dependence of peak and residual strains on the fiber volume fraction was studied. Oxidation of the CMCs in air at 1500 degrees C was studied and the result was explained based on a five part process.