Si-C-O fibre-reinforced ceramic matrix composites: Processing by tape casting and properties

摘要

A new method to produce long fibre ceramic matrix composites is presented. Tape casting, transposed to the fabrication of prepreg leads to a good penetration of the matrix into SiC fibre plies and increases the green density and the homogeneity of the composite at a macrostructural scale. The dispersion of the MAS-L powder and the formulation of the tape casting slurry have been optimized to produce high impregnated prepreg sheets. After thermocompression at 125°C with 100 MPa, green bodiesexhibited 61% of the composite theoretical density. Ultrasonic measurements of Young's modulus have been performed at high temperature on the matrix alone and on the composites. The microstructure of the matrix is stable up to 1200°C. Therefore, evolution of the elastic properties of the composite at high temperature has been attributed to mechanisms at the fibre/matrix interface.