Multilayer fiber-matrix ceramic composite material and process for its production

A process for the production of a composite material comprising a glass, vitreous ceramic and/or ceramic matrix reinforced by long ceramic fibers, and comprising the steps of:

• filling the interstices of a fibrous structure with at least a first precursor in the fluid state and with at least one second precursor in the form of discrete particles;
• and heat treating the whole to convert the first precursor and the second precursor into a continuous matrix, said process further comprising the steps of forming the fibrous structure by stacking woven or nonwoven long fiber sheets previously filled with the precursors for the preparation of the glass, vitreous ceramic or ceramic matrix by the sol-gel route by hydrolysis and polycondensation using alcoxides or analogous compounds as the starting materials, the first precursor being an interface precursor in the form of a gel rich in water and the particles of the second precursor being a matrix precursor containing only a few percent by mass of water and being able to sinter at a temperature substantially lower than the corresponding final composition, and wherein the fibrous structure is compressed in the direction of stacking, during the heat treatment, in order to achieve a good contact between the particles of the matrix precursor and in order to allow the gel to flow and substantially to fill all of the intersticial spaces of the fibrous structure and the particles, wherein at least one interface precursor leads, during the heat treatment of the stack of filled fiber sheets, to the formation of a molten composition which reacts with one or more adjacent solid compositions, of different chemical formulae, resulting from one or more different interface precursors and/or matrix precursors, in order to form a solid composition at the same temperature.