Abstract: A method of fabricating a part made of ceramic matrix composite material, the method includes fabricating the part by forming a ceramic matrix in the pores of a fiber structure, the ceramic matrix being formed by self propagating high temperature synthesis from a powder composition present in the pores of the fiber structure,

Abstract: A method of treating silicon carbide fibers comprises phosphating heat treatment in a reactive gas so as to form a coating around each fiber for protection against oxidation. The coating comprises a surface layer of silicon pyrophosphate crystals and at least one underlying bilayer system comprising a layer of a phosphosilicate glass and a layer of microporous carbon.

Abstract: A method of treating ceramic fibers based on metal carbide, the method including a first reagent gas heat treatment performed with at least one first reagent gas of the halogen type that chemically transforms the surface of the fiber to obtain a surface layer constituted mainly of carbon, and a second reagent gas heat treatment performed with at least one second reagent gas that eliminates the surface layer formed during the chemical transformation.

Abstract: The invention relates to a nuclear fuel cladding totally or partially made of a composite material with a ceramic matrix containing silicon carbide (SiC) fibers as a matrix reinforcement and an interphase layer provided between the matrix and the fibers, the matrix including silicon carbide as well as at least one of the following additional carbides: titanium carbide (TiC), zirconium carbide (Zrc), and ternary titanium silicon carbide (Ti3SiC2). When irradiated and at temperatures of between 800° C. and 1200° C., said cladding can mechanically maintain the nuclear fuel within the cladding while enabling optimal thermal-energy transfer towards the coolant. The invention also relates to a method for making the nuclear fuel cladding.

Abstract: The method comprises the steps of: forming a porous fiber-reinforcing structure; introducing into the pores of the fiber structure powders containing elements for constituting the composite material matrix; and forming at least a main fraction of the matrix from said powders by causing a reaction to take place between said powders or between at least a portion of said powders and at least one delivered additional element; the powders introduced into the fiber structure and the delivered additional element(s) comprising elements that form at least one healing discontinuous matrix phase including a boron compound and at least one discontinuous matrix phase including a crack-deflecting compound of lamellar structure. At least a main fraction of the matrix is formed by chemical reaction between the powders introduced into the fiber structure and at least one delivered additional element, or by sintering the powders.

Abstract: After making a carbon fiber preform and prior to completing densification of the preform with a carbon matrix, impregnation is performed with a liquid formed of a sol-gel type solution and/or a colloidal suspension enabling one or more zirconium compounds to be dispersed. The impregnation and the subsequent treatment, up to obtaining the final part, are performed in such a manner as to have, in the final part, grains or crystallites of one or more zirconium compounds presenting a fraction by weight lying in the range 1% to 10% and of composition having at least a majority of the ZrOxCy type with 1?x?2 and 0?y?1.

Abstract: A method of treating silicon carbide fibers comprises phosphating heat treatment in a reactive gas so as to form a coating around each fiber for protection against oxidation. The coating comprises a surface layer of silicon pyrophosphate crystals and at least one underlying bilayer system comprising a layer of a phosphosilicate glass and a layer of microporous carbon.

Abstract: A fiber preform made of carbon fibers is densified with a carbon matrix in a plurality of separate stages. After a first densification stage and before the end of carbon matrix densification, ceramic particles are introduced in order to be dispersed within the composite material part. The introduced particles have a mean size of less than 250 nm and are made at least of a ceramic compound of an element selected from titanium, yttrium, tantalum, and hafnium, the ceramic compound being selected from oxides, nitrides, and mixed oxide, carbide, and/or nitride compounds that do not react with carbon at a temperature of less than 1000° C. and that have a melting point higher than 1800° C.

Abstract: The invention relates to a method of making a refractory carbide layer on the accessible surface of a C/C composite material, the method including a step consisting in placing the composite material in contact with a reactive composition in solid form that contains an atomic proportion greater than or equal to one-third and less than or equal to 95% of a metal that is a precursor of a determined carbide having a melting temperature greater than 2000° C., and an atomic proportion of silicon that is greater than or equal to 5% and less than or equal to two-thirds. The method further includes a step consisting in impregnating the accessible surface of the C/C composite material with the reactive composition melted at a temperature that is greater than or equal to the melting temperature of the metal that is a precursor of a determined carbide.

Abstract: A method for manufacturing a contact temperature sensor to be used at a temperature of use, including a) supplying a carbon fiber; b) heat treating of the fiber at a temperature higher than 800° C. and higher than the temperature of use; c) full layer depositing on the fiber, at a deposition temperature, an electrically insulating ceramic coating layer stable at the temperature of use, the ceramic material chosen among silica (SiO2), zirconia (ZrO2), and alumina (Al2O3); d) heat treating of the fiber, coated with the coating layer, at a temperature higher than the deposition temperature of the coating layer and higher than the temperature of use, or (c?) full layer depositing on the fiber a first coating layer of silicon carbide; d?) full layer depositing the first coating layer a second coating layer of boron nitride; e?) heat treating the fiber thereby obtained at a temperature above the deposition temperatures and the temperature of use of the sensor.

Abstract: A method of fabricating a friction part out of carbon/carbon composite material, the method including obtaining a three-dimensional fiber preform of carbon fibers impregnated with a solution or a suspension enabling a dispersion of refractory metal oxide particles to be left on the fibers of the preform; applying heat treatment to form a metallic carbide by a carboreduction reaction of the refractory oxide with the carbon of the fibers; continuing the heat treatment until the carbide is transformed into carbon by eliminating of the metal; and then densifying the preform with a carbon matrix by chemical vapor infiltration.

Abstract: Within the pores of a porous thermostructural composite material, there is form an aerogel or xerogel made up of a precursor for a refractory material, the precursor is transformed by pyrolysis to obtain an aerogel or xerogel of refractory material, and then it is silicided by being impregnated with a molten silicon type phase. The aerogel or xerogel is formed by impregnating the composite material with a composition containing at least one organic, organometalloid, or organometallic compound in solution, followed by in situ gelling. The method is applicable to improving the tribological properties or the thermal conductivity of C/C or C/SiC composite material parts, or to making such parts leakproof.

Abstract: A method of treating ceramic fibers based on metal carbide, the method including a first reagent gas heat treatment performed with at least one first reagent gas of the halogen type that chemically transforms the surface of the fiber to obtain a surface layer constituted mainly of carbon, and a second reagent gas heat treatment performed with at least one second reagent gas that eliminates the surface layer formed during the chemical transformation.

Abstract: The invention relates to a nuclear fuel cladding totally or partially made of a composite material with a ceramic matrix containing silicon carbide (SiC) fibers as a matrix reinforcement and an interphase layer provided between said matrix and said fibers, the matrix including at least one carbide selected from titanium carbide (TiC), zirconium carbide (ZrC), or ternary titanium silicon carbide (Ti3SiC2). When irradiated and at temperatures of between 800° C. and 1200° C., said cladding can mechanically maintain the nuclear fuel within the cladding while enabling optimal thermal-energy transfer towards the coolant. The invention also relates to a method for making the nuclear fuel cladding.

Abstract: A method of obtaining fiber textures of carbon from a cellulose precursor includes the steps of: spinning cellulose filaments (12) from a viscose solution or a cellulose solution; subjecting the cellulose filaments to washing in water (21); impregnating the washed and non-dried cellulose filaments with an aqueous emulsion (41) of at least one organosilicon additive; drying the impregnated cellulose filaments; and obtaining a fiber texture made up of impregnated and dried cellulose filaments prior to carbonization.

Abstract: The invention relates to a method of making a refractory carbide layer on the accessible surface of a C/C composite material, the method including a step consisting in placing the composite material in contact with a reactive composition in solid form that contains an atomic proportion greater than or equal to one-third and less than or equal to 95% of a metal that is a precursor of a determined carbide having a melting temperature greater than 2000° C., and an atomic proportion of silicon that is greater than or equal to 5% and less than or equal to two-thirds. The method further includes a step consisting in impregnating the accessible surface of the C/C composite material with the reactive composition melted at a temperature that is greater than or equal to the melting temperature of the metal that is a precursor of a determined carbide.

Abstract: After making a carbon fiber preform and prior to completing densification of the preform with a carbon matrix, impregnation is performed with a liquid formed of a sol-gel type solution and/or a colloidal suspension enabling one or more zirconium compounds to be dispersed. The impregnation and the subsequent treatment, up to obtaining the final part, are performed in such a manner as to have, in the final part, grains or crystallites of one or more zirconium compounds presenting a fraction by weight lying in the range 1% to 10% and of composition having at least a majority of the ZrOxCy type with 1?x?2 and 0?y?1.

Abstract: A method for manufacturing a contact temperature sensor to be used at a temperature of use, including a) supplying a carbon fiber; b) heat treating of the fiber at a temperature higher than 800° C. and higher than the temperature of use; c) full layer depositing on the fiber, at a deposition temperature, an electrically insulating ceramic coating layer stable at the temperature of use, the ceramic material chosen among silica (SiO2), zirconia (ZrO2), and alumina (Al2O3); d) heat treating of the fiber, coated with the coating layer, at a temperature higher than the deposition temperature of the coating layer and higher than the temperature of use, or (c?) full layer depositing on the fiber a first coating layer of silicon carbide; d?) full layer depositing the first coating layer a second coating layer of boron nitride; e?) heat treating the fiber thereby obtained at a temperature above the deposition temperatures and the temperature of use of the sensor.

Abstract: A method of fabricating a friction part out of carbon/carbon composite material, the method including obtaining a three-dimensional fiber preform of carbon fibers impregnated with a solution or a suspension enabling a dispersion of refractory metal oxide particles to be left on the fibers of the preform; applying heat treatment to form a metallic carbide by a carboreduction reaction of the refractory oxide with the carbon of the fibers; continuing the heat treatment until the carbide is transformed into carbon by eliminating of the metal; and then densifying the preform with a carbon matrix by chemical vapor infiltration.

Abstract: The method comprises the steps of: forming a porous fiber-reinforcing structure; introducing into the pores of the fiber structure powders containing elements for constituting the composite material matrix; and forming at least a main fraction of the matrix from said powders by causing a reaction to take place between said powders or between at least a portion of said powders and at least one delivered additional element; the powders introduced into the fiber structure and the delivered additional element(s) comprising elements that form at least one healing discontinuous matrix phase including a boron compound and at least one discontinuous matrix phase including a crack-deflecting compound of lamellar structure. At least a main fraction of the matrix is formed by chemical reaction between the powders introduced into the fiber structure and at least one delivered additional element, or by sintering the powders.