The processing of self-healing ceramic matrix composites by a short time and low cost process was studied. This process is based on the deposition of fiber dual interphases by chemical vapor infiltration and on the densification of the matrix by reactive melt infiltration of silicon. To prevent fibers (ex-PAN carbon fibers) from oxidation in service, a self-healing matrix made of reaction bonded silicon carbide and reaction bonded boron carbide was used. Boron carbide is introduced inside the fiber preform from ceramic suspension whereas silicon carbide is formed by the reaction of liquid silicon with a porous carbon xerogel in the preform. The ceramic matrix composites obtained are near net shape, have a bending stress at failure at room temperature around 300 MPa and have shown their ability to self-healing in oxidizing conditions.

Abstractto explain the mechanical properties achieved. One main important result of this study is that LP-SPS can be used in some hybrid processes to densify fiber reinforced CMC.

The processing of dense Ceramic Matrix Composites (CMC) by a short time and so by low cost process was studied. This process is based on (i) the chemical vapor deposition of carbon interphase on the fiber surface, (ii) the introduction of mineral powders inside the multidirectional continuous fiber preform and (iii) the densification of the matrix by Spark Plasma Sintering (SPS). To prevent carbon fibers and interphase from oxidation in service, a self-healing matrix made of silicon nitride and titanium diboride was processed. A thermal treatment of 3 minutes at 1500°C allows to fully consolidate by SPS the composite without fiber degradation. The ceramic matrix composites obtained have an ultimate bending stress at room temperature around 300 MPa and show a self-healing behaviour in oxidizing conditions.