Abstract: The thermostructural composite material is produced by forming a fibrous preform made from refractory fibers coated with a sizing agent. The preform is densified by a refractory matrix, in particular ceramic, while a carbon interphase is provided between the fibers and the matrix. The fibrous preform is made from refractory fibers coated with a sizing agent of the type that leaves behind a carbon residue upon thermal decomposition. The carbon interphase is produced by the thermal degradation of the sizing agent, occurring for example after the preform is made. The sizing agent is chosen among phenolic, acrylic and cellulose resins, and in particular carboxymethylcellulose.

Abstract: A layer (16) forming interphase in a material having a lamellar structure is situated between the fibers of the texture and the matrix, and at least one layer (14) forming control interphase is situated between the surface of the fibers (10) and the lamellar interphase (16) in such a way as to define, for those cracks which have spread through the matrix (18) and the lamellar interphase (16), a preferential propagation zone away from direct contact with the actual fibers (10).

Abstract: A porous structure made of refractory fibers or densified by carrying out a sequential deposition of a matrix, the deposition comprising at least two chemical vapor infiltration phases of an essentially ceramic material separated by a chemical vapor infiltration of a less rigid material chosen among pyrolytic carbon and boron nitride.

Abstract: The process comprises the steps of forming a fibrous reinforcement with silicium carbide fibers, forming on the fibers an intermediate coating designed to constitute an interface between the fibers and a matrix, and forming a matrix in ceramic material within the residual porosity of the fibrous reinforcement. In a step prior to the formation of the intermediate coating, a treatment is carried out by the chemical route for the elimination of the silica present on the surface of the silicium carbide fibers.

Abstract: A method for the adhesive bonding of refractory parts wherein the refractory parts used are porous or capable of becoming porous by thermal treatment; a layer of thickness between 0.1. and 1 mm is interposed between the refractory parts, which layer is essentially formed of an adhesive which, after thermolysis, leaves a porous refractory residue, and fillers constituted by refractory particles of dimensions varying between 1 and 150 microns; the adhesive is thermolyzed so that a porous bond containing the said fillers is made between the porous refractory parts; then the assembly consisting of the refractory parts and the porous bond is densified by chemical vapor deposition of a refractory material.