Abstract: A process for densifying annular porous substrates by chemical vapour infiltration, includes providing a plurality of unit modules including a support plate on which is formed a stack of substrates, the support plate including a central gas inlet opening communicating with an internal volume formed by the central passages of the stacked substrates and gas outlet openings distributed angularly around the central opening, and a thermal mass cylinder disposed around the stack of substrates having a first end integral with the support plate and a second free end, forming stacks of unit modules in the chamber 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.

Abstract: 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.

Abstract: 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.

Abstract: A process for densifying annular porous substrates by chemical vapour infiltration, includes providing a plurality of unit modules including a support plate on which is formed a stack of substrates, the support plate including a central gas inlet opening communicating with an internal volume formed by the central passages of the stacked substrates and gas outlet openings distributed angularly around the central opening, and a thermal mass cylinder disposed around the stack of substrates having a first end integral with the support plate and a second free end, forming stacks of unit modules in the chamber 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.

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 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 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.

Abstract: Fabricating a composite material part comprises the steps of making a consolidated fiber preform, the fibers of the preform being carbon or ceramic fibers that are coated in an interphase formed by at least one layer of pyrolytic carbon (PyC) or of boron-doped carbon (BC). Obtaining a partially densified consolidated fiber preform, where partial densification comprises forming a first matrix phase on the interphase, the first matrix phase comprising a plurality of layers of self-healing material alternating with one or more layers of PyC or of BC. Continuing densification by dispersing carbon and/or ceramic powder within the partially densified consolidated preform and by infiltrating molten silicon or a liquid composition formed for the most part of silicon.

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 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: Fabricating a composite material part comprises the steps of making a consolidated fiber preform, the fibers of the preform being carbon or ceramic fibers that are coated in an interphase formed by at least one layer of pyrolytic carbon (PyC) or of boron-doped carbon (BC). Obtaining a partially densified consolidated fiber preform, where partial densification comprises forming a first matrix phase on the interphase, the first matrix phase comprising a plurality of layers of self-healing material alternating with one or more layers of PyC or of BC. Continuing densification by dispersing carbon and/or ceramic powder within the partially densified consolidated preform and by infiltrating molten silicon or a liquid composition formed for the most part of silicon.

Abstract: 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.

Abstract: To densify thin porous substrates (1) by chemical vapor infiltration, the invention proposes using loading tooling (10) comprising a tubular duct (10) disposed between first and second plates (12, 13) 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 (20) in an infiltration oven having a reactive gas admission inlet (21) connected to the tubular duct (11) to enable a reactive gas to be admitted into the duct which distributes the gas along the main faces on the substrates (1) 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 (10) from its outer envelope (16) and can be removed via the duct (11).

Abstract: To densify thin porous substrates (1) by chemical vapor infiltration, the invention proposes using loading tooling (10) comprising a tubular duct (10) disposed between first and second plates (12, 13) 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 (20) in an infiltration oven having a reactive gas admission inlet (21) connected to the tubular duct (11) to enable a reactive gas to be admitted into the duct which distributes the gas along the main faces on the substrates (1) 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 (10) from its outer envelope (16) and can be removed via the duct (11).

Abstract: To densify thin porous substrates (1) by chemical vapor infiltration, the invention proposes using loading tooling (10) comprising a tubular duct (10) disposed between first and second plates (12, 13) 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 (20) in an infiltration oven having a reactive gas admission inlet (21) connected to the tubular duct (11) to enable a reactive gas to be admitted into the duct which distributes the gas along the main faces on the substrates (1) 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 (10) from its outer envelope (16) and can be removed via the duct (11).

Abstract: To densify thin porous substrates (1) by chemical vapor infiltration, the invention proposes using loading tooling (10) comprising a tubular duct (10) disposed between first and second plates (12, 13) 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 (20) in an infiltration oven having a reactive gas admission inlet (21) connected to the tubular duct (11) to enable a reactive gas to be admitted into the duct which distributes the gas along the main faces on the substrates (1) 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 (10) from its outer envelope (16) and can be removed via the duct (11).