Abstract: A method of fabricating a part out of ceramic matrix composite material, the method including infiltrating a fiber preform with a molten composition including a majority by weight of silicon, the fiber preform including silicon carbide fibers, silicon carbide powder being present in the pores of said preform, a mean size of silicon carbide crystallites in the powder being less than the mean size of the silicon carbide crystallites in the fibers, a ceramic matrix being formed in the pores of the fiber preform during the infiltration so as to obtain the part made of composite material.

Abstract: A turbine ring assembly includes ring sectors made of ceramic matrix composite material forming a turbine ring and a ring support structure having first and second annular flanges, each ring sector having first and second tabs held between the flanges. First and second holder elements secured to the first annular flange being received in first and second openings in the first tab, while first and second holder elements secured to the second annular flange are in first and second openings in the second tab. Radial clearance is being present when cold between the openings and the portions of the holder elements present in the openings. The first and second annular flanges include, on their faces facing the first and second tabs, a plurality of thrust portions distributed in circumferential manner over the flanges, the ends of the tabs, when cold, being in radial abutment against two thrust portions.

Abstract: A device for coating one or more yarns by a vapor deposition method, the device including a treatment chamber extending along a longitudinal axis and having a treatment zone between an internal and an external circumferential wall, and within which at least one yarn is to be coated by performing a vapor deposition method; a conveyor system to transport the at least one yarn through the treatment zone; an injector device to inject a treatment gas phase into the treatment zone through an inlet orifice present in the internal or external circumferential wall; and a removal device to remove the residual gas phase from the treatment zone through an outlet orifice present in the internal or external circumferential wall, the inlet and the outlet orifice being situated in a common plane perpendicular to the longitudinal axis of the chamber and being offset around the circumferential direction of the chamber.

Abstract: A method of fabricating a curved cellular structure includes making an expandable fiber structure by multilayer weaving between layers of warp yarns and layers of weft yarns, the structure having zones of non-interlinking extending in the thickness of the structure, the non-interlinking zones spaced apart from one another by portions of interlinking between layers of weft yarns, the portions of interlinking offset by one or more weft yarns in a direction parallel to the direction of the layers of weft yarns between each series of these planes; impregnating the fiber structure with a resin; expanding the fiber structure on support tooling to form a cell in the fiber structure at each zone of non-interlinking, the tooling also presenting a curved shape corresponding to the shape of the cellular structure that is to be fabricated; and polymerizing the resin of the fiber structure to form a curved cellular structure.

Abstract: A device for coating one or more yarns by a vapor deposition method, the device including a treatment chamber defining a first and a second treatment zone in which at least one yarn is to be coated by performing a vapor deposition method, the first and second zones being separated by a wall and the first zone surrounding the second zone, or being superposed on the second zone; a conveyor system to transport the at least one yarn through the first and second zones; a first injector device to inject a first treatment gas phase into the first zone and a first removal device configured to remove the residual first gas phase from the first zone; and a second injector device configured to inject a second treatment gas phase into the second zone, and a second removal device configured to remove the residual second gas phase from the second zone.

Abstract: A turbine ring assembly includes ring sectors made as a single piece of ceramic matrix composite material and being for mounting on a metal ring support structure, the ring support structure having two tabs extending radially towards a gas flow passage, each ring sector having a first portion forming an annular base with a radially inside face defining the inside face of the turbine ring and an outside face from which there extend two tab-forming portions, the ring sectors having a section that is substantially ? shaped. The tabs of each ring sector fit axially over the tabs of the ring support structure with contact between the tabs of the ring support structure and the tabs of each ring sector when cold. The tabs of each ring sector are held to the ring support structure by pegs passing through holes formed in the tabs of each ring sector.

Abstract: A part for an aircraft turbojet engine nacelle is made of a composite material and includes at least one outer face (S1), a fibrous preform including fiber locks and having a surface(s) delimiting depressions between fiber locks, a covering material which at least partially covers the surface(s) of the fibrous preform and in particular the depressions, and a matrix which binds entirely the covering material and the fibrous preform. The covering material is a fibrous mat and the outer face (S1) is smooth. A method for manufacturing such a part includes manufacturing the fibrous preform, providing a fibrous mat, depositing the fibrous preform and fibrous mat in a mold, dispersing the matrix between the fibers of the preform and mat and consolidating the fibrous preform and mat.

Abstract: A variable section nozzle includes an ejection casing and a plurality of internal flaps arranged in a ring downstream from the ejection casing. Each internal flap is connected to the ejection casing by a movable lever pivotally mounted to the downstream end of the ejection casing. Each lever is movable between a first position in which the internal flaps are in a high position and a second position in which the internal flaps are in a folded-down position. The nozzle includes a plurality of rigid movement transmission parts distributed circumferentially around the ejection casing. Each rigid movement transmission part is connected to two adjacent levers by connecting rods, and to a control actuator. Each rigid movement transmission part can move in a direction corresponding to the axial direction of the nozzle under the action of the control actuator to move the adjacent levers between the first and second positions.

Abstract: A part made of oxide/oxide composite material includes fiber reinforcement constituted by a plurality of warp yarn layers and of weft yarn layers interlinked by three-dimensional weaving, with the spaces present between the reinforcing yarns being filled with a refractory oxide matrix. The fiber reinforcement presents a weave selected from the following weaves: interlock; multi-plain; multi-satin; and multi-serge, with warp and weft thread counts lying in the range 4 yarns/cm to 20 yarns/cm. The fiber reinforcement also presents a fiber volume fraction lying in the range 40% to 51%.

Abstract: An installation for chemical vapor infiltration of porous preforms of three-dimensional shape extending mainly in a longitudinal direction, the installation comprising a reaction chamber of parallelepiped shape, the side walls of the reaction chamber including heater means and a plurality of stacks of loader devices arranged in the reaction chamber. Each loader device being in the form of an enclosure of parallelepiped shape provided with support elements for receiving porous preforms for infiltrating.

Abstract: A variable section nozzle includes an ejection casing and a plurality of internal flaps arranged in a ring downstream from the ejection casing. Each internal flap is connected to the ejection casing by a movable lever pivotally mounted to the downstream end of the ejection casing. Each lever is movable between a first position in which the internal flaps are in a high position and a second position in which the internal flaps are in a folded-down position. The nozzle includes a plurality of rigid movement transmission parts distributed circumferentially around the ejection casing. Each rigid movement transmission part is connected to two adjacent levers by connecting rods, and to a control actuator. Each rigid movement transmission part can move in a direction corresponding to the axial direction of the nozzle under the action of the control actuator to move the adjacent levers between the first and second positions.

Abstract: A sized yarn for subjecting to a textile operation, the yarn including a plurality of ceramic and/or carbon fibers; an interphase coating covering the fibers; and a film covering the interphase coating and including a linear polysiloxane.

Abstract: A turbine ring assembly includes a ring support structure and a plurality of ring sectors made of CMC material and forming a turbine ring, each ring sector including an annular base with respective end portions having edges that are held facing an edge of the end portion of the annular base of a sector that is adjacent in the turbine ring. The assembly includes resilient holder devices for holding the ring sectors in position on the ring support structure, and each resilient holder device includes a spring element present beside the outside face of the ring support structure.

Abstract: A method of fabricating a multi-perforated part out of composite material includes positioning a sand-blasting mask on a preform including a fiber texture impregnated with a polymerized ceramic-precursor resin, the mask having a plurality of openings corresponding to the perforations to be made in the preform; projecting abrasive particles at high speed against the surface of the mask so as to perforate the preform exposed in the openings of the mask; and pyrolyzing the multi-perforated preform so as to form a ceramic matrix in the multi-perforated fiber texture.

Abstract: A process for treating effluent gas containing polycyclic aromatic hydrocarbons includes a step of spray scrubbing with a mineral oil in order to trap the hydrocarbons, wherein the mineral oil includes a mixture of aromatic mineral oil and naphthenic mineral oil.

Abstract: A turbine ring assembly includes a ring support structure and a plurality of CMC ring sectors forming a turbine ring. Each ring sector is K-shaped in radial section, with tabs extending from the outside face of the annular base over end portions of the annular base, the tabs and the end portions of each ring sector being held respectively facing tabs and end portions of ring sectors that are adjacent in the ring. The turbine ring assembly has a plurality of rigid gaskets, each extending axially between adjacent ring sectors, and resilient holder devices exerting a force suitable for holding the gaskets in contact with the end portions or the tabs of two adjacent ring sectors.

Abstract: A loader device for loading porous substrates of three-dimensional shapes extending mainly in a longitudinal direction into a reaction chamber of an infiltration oven for densification of the preforms by directed flow chemical vapor infiltration. The device comprising at least one annular loader stage formed by first and second annular vertical walls arranged coaxially relative to each other and defining between them an annular loader space for the porous substrates to be densified. First and second plates respectively cover the bottom portion and the top portion of the annular loader space. The first and second annular vertical walls include support elements arranged in the annular loader space so as to define between them unit loader cells, each for receiving a respective substrate to be densified. The device also comprises gas feed orifices and gas exhaust orifices in the vicinity of each unit loader cell.

Abstract: A turbine ring sector made of ceramic matrix composite material has a portion forming an annular base with an inner face for defining the inner face of a turbine ring when the ring sector is mounted on a ring support structure and an outer face from which there extends an attachment portion for attaching the ring sector to the ring support structure, the ring sector further including inter-sector faces, each for facing a neighboring ring sector when the ring sector is mounted on the ring support structure; wherein the inter-sector faces are coated in an environmental barrier that is doped with an electrically-conductive compound and that presents at least one slot.

Abstract: A sector for a turbine stator includes vanes made of composite material, each including an airfoil extending between first and second ends. The sector has first and second platforms made of composite material, the first platform having openings in which the first ends of the vanes are engaged, and the second platform having openings in which the second ends of the vanes are engaged. The openings in the first platform present dimensions greater than the dimensions of the first ends of the vanes engaged in the openings so as to leave clearance between the first end of each vane and the opening. Each vane first end engaged in an opening presents dimensions that are less than the dimensions of the airfoil so as to define a shoulder extending around the first end. The shoulder presents dimensions that are greater than the dimensions of the openings in the first platform.

Abstract: A rotor disk blade for a turbine engine, the blade being made of composite material including fiber reinforcement obtained by multilayer weaving of yarns and densified by a matrix. The blade has a portion constituting an airfoil and a blade root forming a single piece, the blade root having two substantially plane opposite lateral flanks that are formed respectively extending the pressure side surface and the suction side surface of the airfoil. The blade root is clamped between two metal plates fastened against the lateral flanks of the blade root by a bolt and a nut passing through the plates and the blade root. The bolt has a head bearing against one of the two plates. The nut has a head bearing against the other plate.