Abstract: A process for depositing a coating on a continuous fibre of carbon or silicon carbide from a precursor of the coating, includes heating a segment of the fibre in the presence of the coating precursor in a microwave field so as to bring the surface of the segment to a temperature allowing the coating to form on the segment from the coating precursor, wherein the segment of fibre is in the presence of a supercritical phase of the precursor of the coating in the reactor and the coating is formed by supercritical phase chemical deposition in the reactor.

Abstract: A method of consolidation includes placing a fibrous preform in the shaping recess of a shaping tool, and supplying the shaping tool with a gas phase to obtain a deposit in the fibrous preform, the shaping tool for the vapor phase chemical infiltration including first and second portions, having respectively first and second shaping zones surrounded by a first and second edge zones, the first and the second shaping zone defining a shaping recess to receive the fibrous preform. A gas injection port is present at least partially in the first or second edge zone and a gas outlet port is present at least partially in the first or second edge zone, the gas injection port and the gas outlet port placing the shaping recess in fluid communication with the outside of the shaping tool. Outer faces of the first and second portion are impermeable to gas.

Abstract: A process for depositing a coating on a continuous fibre of carbon or silicon carbide from a precursor of the coating, includes heating a segment of the fibre in the presence of the coating precursor in a microwave field so as to bring the surface of the segment to a temperature allowing the coating to form on the segment from the coating precursor, wherein the segment of fibre is in the presence of a supercritical phase of the precursor of the coating in the reactor and the coating is formed by supercritical phase chemical deposition in the reactor.

Abstract: A process for depositing a coating on a continuous carbon or silicon carbide fibre from a coating precursor, includes at least heating a segment of the fibre in the presence of the coating precursor in a microwave field so as to bring the surface of the segment to a temperature enabling the coating to be formed on the segment from the coating precursor.

Abstract: A method of chemical vapor infiltration or deposition includes forming silicon carbide in pores of a porous substrate or on a surface of a substrate, the substrate being placed in a reaction enclosure, the silicon carbide being formed from a gas phase introduced into the reaction enclosure, the gas phase including a reagent compound that is a precursor of silicon carbide and that has the following formula in which n is an integer equal to 0 or 1; m is an integer lying in the range 1 to 3; p is an integer lying in the range 0 to 2 with m+p=3; and R designates —H or —CH3; a ratio C/Si between the number of carbon atoms and the number of silicon atoms in the introduced gas phase lying in the range 2 to 3.

Abstract: A process for depositing a coating on a continuous carbon or silicon carbide fibre from a coating precursor, includes at least heating a segment of the fibre in the presence of the coating precursor in a microwave field so as to bring the surface of the segment to a temperature enabling the coating to be formed on the segment from the coating precursor.

Abstract: 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.

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 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 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.

Abstract: A method of chemical vapor infiltration or deposition includes forming silicon carbide in pores of a porous substrate or on a surface of a substrate, the substrate being placed in a reaction enclosure, the silicon carbide being formed from a gas phase introduced into the reaction enclosure, the gas phase including a reagent compound that is a precursor of silicon carbide and that has the following formula in which n is an integer equal to 0 or 1; m is an integer lying in the range 1 to 3; p is an integer lying in the range 0 to 2 with m+p=3; and R designates —H or —CH3; a ratio C/Si between the number of carbon atoms and the number of silicon atoms in the introduced gas phase lying in the range 2 to 3.

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 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 treating at least one silicon carbide fiber, the method including a) putting at least one silicon carbide fiber presenting an oxygen content that is less than or equal to 1% in atomic percentage into contact with an oxidizing medium in order to transform the surface of the fiber chemically and form a surface layer of silica; b) eliminating the resulting silica layer by putting the fiber obtained after performing step a) into contact with an acid liquid medium comprising at least hydrofluoric acid; and c) depositing an interphase layer on the surface of the fiber obtained after performing step b).

Abstract: 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.

Abstract: 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 ?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° 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.

Abstract: A method of densifying a porous substrate with a matrix, includes subdividing the pores present in the porous substrate so as to form in the substrate a network of micropores, the subdividing being performed with a filler composition comprising at least one carbon-containing phase or carbide-containing phase that is accessible via the network of micropores; and infiltrating the network of micropores formed by the filler material by reactive chemical vapor infiltration, the infiltration being performed with a reactive gas composition that does not contain carbon and that includes at least one element suitable for reacting with the carbon of the filler composition in order to form a carbide.

Abstract: A composite material part having a matrix made of ceramic, at least for the most part, is fabricated by a method comprising 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 ?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° 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 preform with a matrix that is made of ceramic, at least for the most part.

Abstract: 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.

Abstract: 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.