Snecma Propulsion Solide

Centre National De La Recherche Scientifique

Messier-bugatti-dowty

Herakles

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Safran Landing Systems

Safran Ceramics

Le Centre National De La Recherche Scientifique

René Pailler

Eric Bouillon

Eric Philippe

Jacques Thebault

Pierre Olry

Sylvie Loison

Sandrine Baud

Pascale Jacquemard

Magali Rollin

Hervé Plaisantin

Sébastien Bertrand

Nicolas Eberling-Fux

Adrien Delcamp

Christian Robin-Brosse

Fabienne Audubert

Jean-Christophe Ichard

Alain Guette

Michel Cataldi

Jean-Christophe Batsale

Jean-Marc Goyheneche

Roman Konig

Michaël Podgorski

Christophe Soumailles

Aurélie Quet

Julien Cabrero

Brice Taillet

Florian Fontaine

Francis Teyssandier

Stéphane Mazerat

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.

Method for processing ceramic fibers

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 (TiSiC). When irradiated and at temperatures of between 800&#xb0; C. and 1200&#xb0; 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.

Nuclear fuel cladding with high heat conductivity and method for making same

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.

Process for manufacturing a part made of a ceramic matrix composite containing matrix phases for healing and deflecting cracks

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 ZrOCtype with 1&#x2266;x&#x2266;2 and 0&#x2266;y&#x2266;1.

Part based on C/C composite material, and a method of fabricating it

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&#xb0; 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.

Method for making a refractory carbide layer on a part made of C/C composite material

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.

Method of fabricating a friction part out of carbon/carbon composite material

A method of obtaining fiber textures of carbon from a cellulose precursor includes the steps of: spinning cellulose filaments () from a viscose solution or a cellulose solution; subjecting the cellulose filaments to washing in water (); impregnating the washed and non-dried cellulose filaments with an aqueous emulsion () 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.

Obtaining fiber textures of carbon by carbonizing a cellulose precursor

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.

Method of siliciding thermostructural composite materials, and parts obtained by the method

The subject of the present invention is a method of obtaining fibrous carbon materials by carbonization of cellulosic fibrous materials carried out continuously or batchwise in the presence of at least one organosilicon compound. Characteristically, said organosilicon compound is chosen from the family of crosslinked, cyclic or branched oligomers and resins, which have a number-average molecular mass of between 500 and 10 000 and which consist of units of formula SiO(called Qunits) and units of formula SiOR(OR').

Carbonization of cellulosic fibrous materials in the presence of an organosilicon compound

Growing community of inventors

Cestas, France

René Pailler