Abstract: The present disclosure relates to an apparatus for fluidised-bed chemical vapour deposition from a gaseous phase allowing the temperature of the fluidised bed to be stabilised during the deposition and also to an associated method for its implementation, the apparatus being characterised in that it comprises a porous thermal insulator present in an inlet zone and configured to be passed through by the gaseous phase, said porous thermal insulator having an effective thermal conductivity at 20° C. less than or equal to 3.5 W·m-1·K-1.

Abstract: A process for manufacturing a ceramic matrix composite part, includes infiltrating a fibrous structure including a powder composition with a melt infiltration composition including at least silicon in order to form a ceramic matrix in the porosity of the fibrous structure, the powder composition including at least silicon carbide particles, wherein the silicon carbide particles have a bimodal size distribution with a first set of silicon carbide particles having a first average size and a second set of silicon carbide particles having a second average size smaller than the first average size, the number of particles in the first set being greater than the number of particles in the second set.

Abstract: A nozzle for a turbomachine turbine. The nozzle includes blades made of ceramic matrix composite material, and at least one metal liner passing through a respective blade. The liner is connected in a sealed manner to a metal internal shroud so as to guide a ventilation fluid through the blade. The nozzle can be configured to maintain effective sealing in spite of the different thermal expansions of the blade and of the internal shroud.

Abstract: A method for manufacturing a turbine nozzle vane made of ceramic matrix composite material, wherein the vane is manufactured using a first fibrous preform including a hollow central section intended to form a fibrous reinforcement of an airfoil of the vane to be obtained, and a pair of second fibrous preforms each having an opening with a shape of the airfoil of the vane to be obtained.

Abstract: A method for treating an aromatic mineral oil or a mixture of aromatic mineral oil and naphthenic mineral oil, the oil or the mixture of oils being loaded with polycyclic aromatic hydrocarbons, the method including a—optional removal of polycyclic aromatic hydrocarbon s having a molecular weight greater than or equal to 200 from the aromatic mineral oil or the mixture of aromatic mineral oil and naphthenic mineral oil loaded with polycyclic aromatic hydrocarbons; b—extraction, at a pressure lower than atmospheric pressure, of polycyclic aromatic hydrocarbons having a molecular weight lower than 200 solubilised in the oil or the mixture of oils obtained in step (a); and c—recovery of the oil or the mixture of oils depleted in polycyclic aromatic hydrocarbons.

Abstract: Method for manufacturing a CMC, i.e. ceramic matrix composite material, part provided with at least one cutout, as well as to such a CMC part provided with at least one cutout, the method comprising the following steps: providing (E1) a fibrous reinforcement (10), forming (E2?) a cavity in a portion of the fibrous reinforcement (10), injecting (E3) a slip comprising at least a ceramic powder and a solvent, the slip being injected so as to impregnate the fibrous reinforcement (10?) and to fill the cavity of the fibrous reinforcement (10?), drying (E4) the obtained assembly, carrying out a densification (E6) by infiltration of a liquid densification material and solidification of said densification material, machining (E7) at least one cutout in the obtained blank (30) within the volume corresponding to the cavity of the fibrous reinforcement (10).

Abstract: A method for manufacturing a part made of composite material includes forming a ceramic matrix phase in pores of a fibrous preform by pyrolysis of a cross-linked copolymer ceramic precursor, the cross-linked copolymer including a first precursor macromolecular chain of a first ceramic having free carbon, and a second precursor macromolecular chain of a second ceramic having free silicon, the first macromolecular chain being bonded to the second macromolecular chain by cross-linking bridges including a bonding structure of formula *1—X—*2; in this formula, X designates boron or aluminium, -*1 designates the bond to the first macromolecular chain and -*2 the bond to the second macromolecular chain.

Abstract: A method for manufacturing a part made of composite material in which an adhesion promoter is grafted to a coating present on the fibre surface as well as to a ceramic precursor resin. Afterwards, a ceramic matrix phase is formed in the porosity of the fibre preform by pyrolysis of the polymerised resin.

Abstract: A manufacturing process of a fibrous preform for a composite material includes creating a fibrous texture by three-dimensional or multilayer weaving between a plurality of weft layers and warp layers, the fibrous texture including an extra-thick portion having a sacrificial portion and a useful portion adjacent to the sacrificial portion in the warp direction, the sacrificial portion, placing the fibrous texture in a forming toolset, shaping the fibrous texture so as to obtain a fibrous preform having a sacrificial portion and an adjacent useful portion, removing the sacrificial portion from the fibrous preform. When weaving the fibrous blank, one or more expansion elements are inserted into the weft layers located at the core of the sacrificial portion of the fibrous texture. Each expansion element has a cross-section greater than the cross-section or count of the weft threads or strands present in the useful portion.

Abstract: A method for manufacturing an environmental barrier comprising the steps of coating a rare earth silicate powder with a precursor of a densification agent in order to form a rare earth silicate powder coated with the precursor of the densification agent, thermally spraying the coated powder onto a substrate in order to obtain an at least partially amorphous environmental barrier on the substrate and thermally treating the environmental barrier in order to crystallize and densify the environmental barrier.

Abstract: A part includes a substrate, having, adjacent to a surface of the substrate, at least a portion that is made from a material that contains silicon, and an environmental barrier formed on the surface of the substrate, the environmental barrier including at least a first layer including a rare earth disilicate of formula REa2Si2O7 present at a molar content lying in the range 70% to 99.9%, where REa is a rare earth element; and at least one rare earth oxide of formula REb2O3 present at a molar content lying in the range 0.1% to 30%, where REb is a rare earth element different from REa.

Abstract: A turbomachine turbine nozzle extending around a central axis, including at least one radially outer shroud, at least one radially inner shroud, and at least one blade made of ceramic matrix composite material, distinct from the radially inner shroud and from the radially outer shroud, and extending radially between the radially inner shroud and the radially outer shroud, the blade being hollow and including a cavity opening at a radially inner end and at a radially outer end of the blade, the nozzle including at least one tubular mast arranged in the cavity of the blade and allowing routing the ventilation air passing through the cavity of the blade, the mast including a radially outer end attached to the radially outer shroud, and a radially inner end cooperating with a radial flange for positioning the radially inner shroud.

Abstract: The present disclosure relates to an apparatus for fluidised-bed chemical vapour deposition from a gaseous phase allowing the temperature of the fluidised bed to be stabilised during the deposition and also to an associated method for its implementation, the apparatus being characterised in that it comprises a porous thermal insulator present in an inlet zone and configured to be passed through by the gaseous phase, said porous thermal insulator having an effective thermal conductivity at 20° C. less than or equal to 3.5 W·m-1·K-1.

Abstract: A method for densifying one or more porous substrates with pyrolytic carbon by chemical vapour infiltration, includes admitting, at the inlet of the densification furnace, a reactive gaseous phase including at least one pyrolytic carbon precursor; reacting at least a fraction of the reactive gaseous phase with the porous substrate or substrates; extracting, at the outlet of the densification furnace, gaseous effluents originating from the reactive gaseous phase; reintroducing, with the reactive gaseous phase admitted at the inlet of the densification furnace, at least a fraction of the gaseous effluents extracted at the outlet of the furnace, wherein the fraction of the gaseous effluents introduced with the reactive gaseous phase includes at least one polyaromatic hydrocarbon compound.

Abstract: The invention relates to the production of a composite material of a lobed structure (10) of a flow mixer which comprises a portion having a plurality of lobes (17, 19). For this purpose, a fibrous preform containing a resin will be produced in a simple geometric configuration of developable revolution. This is an intermediate state. By exploiting the thermoformable or thermosetting nature of the resin, the geometry of this intermediate preform is modified to deform it with limited offsets towards the final geometry.

Abstract: A method for injecting a loaded suspension into a fibrous texture having a three-dimensional or multilayer weaving includes the injection of a suspension containing a powder of solid particles into the volume of the fibrous texture. The injection of the loaded suspension is carried out by at least one hollow needle in communication with a loaded suspension supply device, each needle being movable in at least one direction extending between a first face and a second opposite face of the fibrous texture so as to inject the loaded suspension at one or more determined depths in the fibrous texture.

Abstract: A turbine stator blade made of ceramic matrix composite material includes a hollow blade profile and has a trailing edge and a leading edge, the blade including a first portion including an extrados face and a second portion distinct from the first portion including an intrados face, the first and second portions being connected to one another by a connection interface present at least on the trailing edge or leading edge, the connecting interface including a region of overlap between the first and second portions present on at least one longitudinal end of the blade profile and intended to be present outside a flow path of a gas stream of the turbine, the blade also including a platform present at a longitudinal end of the blade profile and that includes a first portion integral with the extrados face and a second part integral with the intrados face.

Abstract: A method for producing a hollow part made of a ceramic matrix composite material. The method includes shaping a hollow fibrous preform. A core of oxidizable material is housed or inserted into the preform. The method also includes consolidating the preform and extracting the core by oxidising the core.

Abstract: An assembly for a turbomachine turbine includes a housing (1) extending circumferentially about an axis X, sectors (2) intended to form a ring capable of delimiting a gas flow path, each sector (2) comprising a first side (17) and a second side (18) extending radially and circumferentially about the said axis X and spaced axially from each other, each side (17, 18) of the sector (2) including at least one radial bearing surface of an oblong hole capable of cooperating with support pins (13, 14) of the housing (1), at least one of the sides (17, 18) including means (23) for the circumferential positioning of the sector (2) with respect to the housing (1), wherein each radial bearing surface is cylindrical relative to axis X and is capable of bearing on a complementary cylindrical surface relative to axis X of a support pin.

Abstract: A process for depositing a coating on short fibres of carbon or silicon carbide from a coating precursor, the short fibres having a length of between 50 ?m and 5 mm, the process including at least heating the short fibres by placing a mixture including the fibres and a liquid phase of the coating precursor in a microwave field so as to bring the surface of the fibres to a temperature allowing the coating on the fibres from the coating precursor to be formed by calefaction.