Safran Ceramics

Snecma Propulsion Solide

Herakles

Centre National De La Recherche Scientifique

Safran Landing Systems

Sébastien Bertrand

Franck Lamouroux

Stéphane Goujard

Adrien Delcamp

Alain Caillaud

Eric Bouillon

Eric Philippe

Bruno C Bernard

Stephane R Goujard

Francis Bagilet

Stéphane Mazereau

Matthieu Champagne

Jeff Roustand

Jacques Thebault

Nicolas Eberling-Fux

René Pailler

Christian Robin-Brosse

Cédric Descamps

Sylvain Jacques

Stéphane Roger André Goujard

Jean-Luc Domblides

Simon Thibaud

Rémy Dupont

Jean-Christophe Ichard

Caroline Louchet

Franck Beauvais

Robert Bagat

Olivier Clausse

Jean-Michel Garcia

Cedric Descamps

Bruno Bernard

A method for densifying porous annular substrates having a central passage by chemical vapor infiltration, the method including providing stacks of porous annular substrates, providing a plurality of individual modules including stacks disposed on a support plate having a perforated injection tube each mounted on a gas inlet opening, forming a stack of individual modules, aligning the individual modules of the stack in a sealed manner by means of an annular seal disposed between the injection tube of a second individual module and the gas inlet opening of a first individual module with which it cooperates, and injecting into the internal volume of each stack of porous annular substrates a gas phase including a gaseous precursor of a matrix material to be deposited within the porosities of the substrates.

Chemical vapor infiltration densification method using single-pile plates for a semi-forced flow

A method for densifying porous annular substrates by chemical vapor infiltration, includes providing a plurality of unit modules including a support tray on which substrates are stacked, the support tray including a gas intake opening extended by an injection tube disposed in an internal volume formed by the central passages of the stacked substrates, the injection tube including gas injection orifices opening into the internal volume, forming stacks of unit modules in the enclosure of a densification furnace and injecting, into the stacks of unit modules, a gas phase including a gas precursor of a matrix material to be deposited within the porosity of the substrates.

Method for densifying porous annular substrates by chemical vapour infiltration

A shaping tooling for chemical vapor infiltration of a fiber preform includes a structural enclosure formed by supports each provided with a multiply-perforated zone. Each of the supports has in its inside face an uncased zone that includes the multiply-perforated zone. The shaping tooling further includes first and second shaping mold functional elements, each present in a respective one of the uncased zones of the support. Each shaping mold functional element has a first face of a determined shape corresponding to the shape of the part that is to be made and a second face that is held facing the inside face of a support. Each functional element has a plurality of perforations and presents a number of perforations, a size of perforations, or a shape of perforations that differs from the number, the size, or the shape of the perforations present in the facing support.

Shaping equipment and facility for gas-phase chemical infiltration of fibrous preforms

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.

Chemical vapour infiltration apparatus having a high loading capacity

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.

Device for loading porous substrates of three-dimensional shape in order to be densified by directed flow chemical vapor infiltration

A loader device is arranged for densifying porous preforms of stackable shape by means of directed stream chemical vapor infiltration in a reaction chamber of an infiltration oven. The device comprises a support tray, a first stack having a plurality of bottom rings arranged on the support tray and a plurality of injection orifices, a second stack comprising a plurality of top rings and a plurality of discharge orifices extending between the outer periphery and inner periphery of each ring. The device includes a first non-porous wall corresponding to the porous preforms and arranged on the support tray inside the bottom rings of the first stack, and a second non-porous wall corresponding to the porous preforms extending between the bottom ring situated at the top of the first stack and the top ring situated at the top of the second stack.

Loader device and an installation for densifying stackable frustoconical porous preforms

A composite material part having a matrix made of ceramic, at least for the most part, is fabricated by a method including making a fiber preform from silicon carbide fibers containing less than 1 at % oxygen; depositing a boron nitride interphase on the fibers of the preform, deposition being performed by chemical vapor infiltration at a deposition rate of less than 0.3 &#x3bc;m/h; performing heat treatment to stabilize the boron nitride of the interphase, after the interphase has been deposited, without prior exposure of the interphase to an oxidizing atmosphere and before depositing matrix layer on the interphase, the heat treatment being performed at a temperature higher than 1300&#xb0; C. and not less than the maximum temperature to be encountered subsequently until the densification of the preform with the matrix has been completed; and thereafter, densifying the perform with a matrix that is made of ceramic, at least for the most part.

Method for manufacturing a part made of CMC

A part made of ceramic matrix composite material has fiber reinforcement of carbon or ceramic fibers and a majority-ceramic sequenced matrix having first matrix layers made of crack-deflector material alternating with second matrix layers made of ceramic material. An interphase coating is interposed between the fibers and the matrix, and the interphase coating adheres to the fibers and to the matrix, and is formed of at least one sequence constituted by a first elementary layer made of carbon, possibly doped with boron, surmounted by a second elementary layer made of ceramic. The outer elementary interphase layer of the coating is a ceramic layer having an outer surface formed by ceramic grains of size lying essentially in the range 20 nm to 200 nm, with the presence of grains of size greater than 50 nm conferring roughness on the outer surface ensuring mechanical attachment with the adjacent matrix phase.

Ceramic matrix composite material part

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

To densify thin porous substrates () by chemical vapor infiltration, the invention proposes using loading tooling () comprising a tubular duct () disposed between first and second plates () and around which the thin substrates for densification are disposed radially. The tooling as loaded in this way is then placed inside a reaction chamber () in an infiltration oven having a reactive gas admission inlet () connected to the tubular duct () to enable a reactive gas to be admitted into the duct which distributes the gas along the main faces on the substrates () in a flow direction that is essentially radial. The reactive gas can also flow in the opposite direction, i.e. it can be admitted into the tooling () from its outer envelope () and can be removed via the duct ().

Method of densifying thin porous substrates by chemical vapor infiltration, and a loading device for such substrates

A method of densifying a porous substrate with pyrolytic carbon includes loading the substrate into an oven, admitting a reaction gas mixture to the oven, extracting an effluent gas from the oven, and recycling components of the effluent gas into the reaction gas mixture. The reaction gas mixture contains a pyrolytic carbon precursor gas together with a vector gas. The effluent gas contains residual components of the reaction gas mixture together with reaction products, including hydrogen. The recycling is performed after eliminating heavy hydrocarbons contained in the effluent gas.

Method for chemical infiltration in the gas phase for the densification of porous substrates with pyrolytic carbon

An interphase coating is formed by chemical vapor infiltration (CVI) on the fibers constituting a fiber preform, the interphase coating comprising at least an inner layer in contact with the fibers for embrittlement relief to the composite material, and an outer layer for bonding with the ceramic matrix. The fiber preform is then kept in its shape by the fibers provided with the interphase coating and is consolidated by being impregnated with a liquid composition containing a ceramic precursor, and by transforming the precursor into a ceramic matrix consolidation phase. The consolidated preform is then densified by an additional ceramic matrix phase. No support tooling is needed for forming the interphase coating by CVI or for densification after consolidation using the liquid technique.

Method for making a part of composite material with ceramic matrix and resulting part

A method of densifying porous substrates by chemical vapor infiltration comprises loading porous substrates for densification in a loading zone of an enclosure (), heating the internal volume of the enclosure, and introducing a reagent gas into the enclosure though an inlet situated at one end of the enclosure. Before coming into contact with substrates () situated in the loading zone, the reagent gas admitted into the enclosure is preheated, at least in part, by passing along a duct () connected to the gas inlet and extending through the loading zone, the duct being raised to the temperature inside the enclosure, and the preheated reagent gas is distributed in the loading zone through one or more openings () formed in the side wall () of the duct, along the duct.

Growing community of inventors

Moulis en Medoc, France

Sébastien Bertrand