Apparatus comprising a removable tool for infiltration in the gas phase

Abstract

The invention relates to a removable tool (100) for consolidation or densification in the gas phase of at least one fibrous preform (5) configured to be arranged in an oven (10, 20), the removable tool (100) being characterised in that it comprises a homogenisation chamber (110) comprising at least one gas inlet orifice (111) and a depletion chamber (130) comprising at least one gas outlet orifice (131), the removable tool (100) further comprising a reaction chamber (120) arranged between the homogenisation chamber (110) and the depletion chamber (130) and configured to receive at least one fibrous preform (5), the reaction chamber (120) being separated from the homogenisation chamber (110) and the depletion chamber (130) by perforated plates (115, 125).

Description

[0001] Description

[0002] INSTALLATION INCLUDING REMOVABLE TOOLS FOR GAS PHASE INFILTRATION

[0003] Technical field

[0004] The present invention relates to the manufacture of parts made of composite material and, more particularly, to the installation and tools used during the consolidation or densification by chemical infiltration in the gas phase of a fibrous preform intended to form at least the reinforcement of the part made of composite material.

[0005] Prior art

[0006] Consolidation or densification by chemical vapor infiltration, also called "CVI", is conventionally carried out by loading the fiber preform(s) to be consolidated or densified into a furnace. Such a furnace is described in particular in documents WO 2018 / 104640 A1 and WO 2015 / 044562 A1.

[0007] The furnace usually comprises a reactive gas injection zone containing one or more gaseous precursors of the matrix material. These reactive gases are then introduced into a homogenization zone of the furnace, making it possible to homogenize the temperature and composition of said gases, before entering a reaction zone in which the preforms to be densified or consolidated are arranged.

[0008] The temperature and pressure in the furnace are adjusted to allow the reactive gas to diffuse into the porosities of the fiber preforms. The reactive gas can thus form a deposit of the matrix material by decomposition of one or more constituents of the reactive gas or reaction between several constituents, these constituents forming the precursor of the matrix.

[0009] The gases then enter a depletion zone, where they are consumed before being evacuated through a gas ejection zone. However, this consolidation or densification technique involves long production cycles, especially compared to the time actually used to densify or consolidate the preform. Indeed, before the actual densification or consolidation can be carried out, it is necessary to load the fiber preform(s) into the furnace, measure the furnace leakage rate, and heat the furnace to reach the desired temperature. Once the densification or consolidation step has been completed, it is still necessary to cool the furnace, unload the part(s), and then clean and prepare the furnace for the next cycle.

[0010] Statement of the invention

[0011] The present invention aims to remedy the drawbacks described above.

[0012] To this end, the invention proposes a removable tool for the consolidation or densification in the gas phase of at least one fiber preform configured to be placed in an oven, the removable tool being characterized in that it comprises a homogenization chamber comprising at least one gas inlet orifice and a depletion chamber comprising at least one gas outlet orifice, the removable tool further comprising a reaction chamber arranged between the homogenization chamber and the depletion chamber and configured to receive at least one fiber preform, the reaction chamber being separated from the homogenization and depletion chambers by perforated plates.

[0013] "Homogenization chamber" means a chamber configured to homogenize the composition and temperature of the gas(es) entering through the gas inlet(s). "Depletion chamber" means a chamber configured to deplete the gas(es) before exiting through the gas outlet(s). "Oven" preferably means a furnace configured for chemical gas infiltration operations.

[0014] Thus, the removable tooling according to the invention makes it possible to significantly increase the time during which the furnace for chemical gas infiltration is available to effectively carry out densification or consolidation operations. Indeed, the homogenization, reaction and depletion zones are the zones which require recurring cleaning and maintenance, because they are the zones most exposed to reactive gases. By using removable tooling directly integrating the homogenization zone, the reaction zone and the depletion zone, it is possible to carry out recurring cleaning, maintenance and preparation operations without immobilizing the furnace. Thus, the cleaning and preparation steps can be carried out on a first removable tooling while the furnace is simultaneously used, for example to densify or consolidate fiber preforms using a second removable tooling.

[0015] Furthermore, thanks to such removable tools, it is possible to maintain the furnace at the correct temperature and pressure conditions by loading and unloading the removable tools. It is therefore no longer necessary to carry out the heating and cooling steps of the furnace, which remains at temperature, while the removable tools are heated or cooled separately.

[0016] Thus, thanks to such removable tooling, the use of the furnace for chemical infiltration in the gas phase is almost exclusively limited to the densification or consolidation operation, thus greatly increasing the possible production rate.

[0017] Furthermore, the use of such removable equipment allows for savings in reactive gases, because the reaction zone - here limited to the reaction chamber - is very small. This reduction in reactive gas consumption also allows for a reduction in installation costs, by allowing for a more modest sizing of the furnace, in particular concerning the vacuum group or the effluent treatment unit.

[0018] According to another particular characteristic of the invention, the removable tool is made at least partially of conductive material and comprises electrical connection terminals.

[0019] Thus, the removable tooling can be connected to electrical terminals present in the furnace, so as to act as a resistance. The removable tooling can thus be capable of heating the fiber preforms present in its reaction chamber and possibly the reactive gas(es) present in said removable tooling.

[0020] According to a particular characteristic of the invention, the removable tool is made of graphite.

[0021] The invention also relates to a load configured to be placed in a furnace, said load comprising removable tooling according to the invention and at least one fibrous preform placed in the reaction chamber of the removable tooling.

[0022] According to a particular characteristic of the invention, the loading comprises at least one shaper in which the fiber preform is held, the shaper being arranged in the reaction chamber of the removable tool.

[0023] Thus, the fiber preform(s) can be freely arranged in the reaction chamber of the removable tool, or be held in one or more formers.

[0024] According to a particular characteristic of the invention, said at least one shaper comprises a plurality of shaping housings, each shaping housing being formed by a first surface and a second surface facing each other and being intended to accommodate a fiber preform, each first or second surface comprising holding elements projecting relative to said surface and extending to an end face intended to be in contact with the fiber preform, each shaping housing extending between at least one gas inlet and at least one gas outlet positioned between the first surface and the second surface of said housing.

[0025] The term "end face" refers to the surface of the holding element which is actually in contact with the fiber preform arranged in the shaping housing. Thus, the entire end face of a holding element must be in contact with the fiber preform when the latter is arranged in the shaping housing.

[0026] Such a former is perfectly suited to removable tooling according to the invention, and makes it possible to further reduce the consumption of reactive gases while increasing the quantity of fiber preforms that can be consolidated or densified simultaneously. In addition, this type of former without perforations requires little maintenance and cleaning operations, while being more robust.

[0027] The invention further relates to an installation for consolidation or densification by chemical gas infiltration comprising at least one removable tool according to the invention, said installation further comprising at least one CVI furnace comprising at least one gas injector and a gas evacuation system, the CVI furnace being capable of receiving the removable tool such that at least one gas inlet orifice of the removable tool is connected to at least one gas injector of the CVI furnace, the CVI furnace being configured to heat or thermally insulate said removable tool.

[0028] By "CVI furnace" we mean a CVI type furnace, from the English "chemical vapor infiltration", that is to say a furnace configured to carry out a gas phase infiltration operation.

[0029] The presence of several CVI furnaces in the installation makes it possible to increase the production rate, but can also offer greater flexibility and allow more variations in the implementation of consolidation and densification processes, or even in the implementation of mixed processes. Thus, the same loaded removable tool can be placed successively in two CVI furnaces, presenting for example different conditions of temperature, pressure or composition of the injected gas(es).

[0030] According to a particular characteristic of the invention, in the case where the removable tool is made at least partially of conductive material and comprises electrical connection terminals, the CVI oven further comprises electrical connection terminals, the CVI oven being capable of receiving the removable tool so that the electrical connection terminals of the CVI oven are connected to the electrical connection terminals of the removable tool.

[0031] Thus, the removable tooling can act as a resistor, and thus be capable of heating the fiber preforms present in its reaction chamber and possibly the reactive gas(es) present in said removable tooling. According to a particular characteristic of the invention, the installation further comprises at least one preheating furnace capable of receiving a removable tooling according to the invention and configured to preheat or thermally insulate said removable tooling.

[0032] The presence of a preheating furnace makes it possible to carry out preheating, i.e. the heating up, or even the pressurization, of the removable tool loaded by the fiber preform(s) without requiring the blocking of a CVI furnace configured for consolidation or densification in the gas phase. The CVI furnace(s) can thus be dedicated to the actual consolidation or densification step, with the preheating of the loads being carried out in the preheating furnace(s). Production rates can thus be increased.

[0033] According to another particular characteristic of the invention, the installation further comprises at least one cooling cell capable of receiving removable tools according to the invention and configured to cool said removable tools.

[0034] The presence of a cooling cell makes it possible to cool the removable tool loaded by the consolidated or densified part(s) without requiring the blocking of a CVI furnace configured for gas phase consolidation or densification. The CVI furnace(s) can thus be dedicated to the actual consolidation or densification step, with the cooling of the consolidated or densified parts being carried out in the cooling cell(s). Production rates can thus be increased.

[0035] The removable tooling therefore conventionally leaves the installation according to the invention from the cooling cell. However, the cooling cell can also be the entrance from which the removable tooling enters the installation according to the invention. Indeed, by loading the removable tooling into the cooling cell before making it enter via a transfer tunnel into a preheating furnace or into a CVI furnace, the heat losses from the preheating furnace or the CVI furnace are limited compared to if said preheating furnace or CVI were directly open to the outside. According to another particular characteristic of the invention, the installation comprises at least one transfer tunnel configured to allow the movement of the removable tooling at least between the CVI furnace and another CVI furnace, a preheating furnace or a cooling cell.

[0036] The use of such a transfer tunnel allows removable tooling to be easily moved between the CVI furnace(s), the preheating furnace(s) and the cooling cell(s).

[0037] Preferably, the transfer tunnel comprises at least two openings, and forms a closed passage allowing the movement of the shaping tooling. Preferably, each opening of the transfer tunnel is capable of forming a sealed contact with the door of the CVI furnace, the preheating furnace or the cooling cell.

[0038] Preferably, the transfer tunnel is made at least partially of an adiabatic material, that is to say of a material preventing the exchange of heat between the outside and the inside of the tunnel. Thus, by limiting the heat losses of the removable tooling during its passage in the transfer tunnel, its temperature is maintained, which is particularly advantageous in the case of a transfer between two furnaces of the installation.

[0039] The installation therefore has a modular configuration, with each CVI furnace, each preheating furnace and each cooling cell corresponding to a module. Such an architecture with several modules allows great flexibility in carrying out chemical gas infiltration processes. Thus, a loaded removable tool can move from one module to another easily, depending on the steps to be carried out.

[0040] The invention also relates to a use of an installation for consolidation or densification by chemical infiltration in the gas phase comprising at least one CVI furnace, a preheating furnace and a cooling cell, the CVI furnace comprising at least one gas injector and a gas evacuation system, the use comprising: - the placement of a load according to the invention in the preheating furnace, and the preheating of said load, then

[0041] - placing the load in the CVI furnace so that at least one gas inlet of the removable tooling of the load is connected to at least one gas injector of the CVI furnace, then consolidation or densification by gas infiltration of a matrix of the fiber preform(s) present in the load, then

[0042] - placing the load in the cooling cell, and cooling said load, then

[0043] - removal of the load from the cooling cell.

[0044] Then, the part(s) consolidated or densified by the matrix can be removed from the removable tool.

[0045] The use described here represents a conventional use of the consolidation or densification installation. Of course, it does not depart from the scope of the invention if additional steps are added.

[0046] More generally, the invention relates to a use of an installation for consolidation or densification by chemical infiltration in the gas phase comprising at least one CVI furnace, the CVI furnace comprising at least one gas injector and a gas evacuation system, the use comprising:

[0047] - placing a load according to the invention in the CVI furnace so that at least one gas inlet orifice of the removable tooling of the load is connected to at least one gas injector of the CVI furnace, then consolidation or densification by gas phase infiltration of a matrix of the fiber preform(s) present in the load, then

[0048] - removal of the load from the CVI oven.

[0049] According to a particular characteristic of the invention, the use of the installation further comprises, before placing the load in the CVI furnace, placing the load in a preheating furnace, then preheating said load. According to another particular characteristic of the invention, the use of the installation further comprises, after the consolidation or densification step by gas infiltration, placing the load in a cooling cell, then cooling said load.

[0050] In the case where the preceding use concerns the consolidation of fibrous preforms, an additional step of densification by gas, liquid or solid means can be carried out in a well-known manner to obtain a part made of composite material. The additional step of densification by gas can be carried out using the removable tooling or the installation according to the invention.

[0051] Brief description of the drawings

[0052] [Fig. 1] Figure 1 is a schematic view in transparent perspective of a load comprising removable tools according to the invention.

[0053] [Fig. 2] Figure 2 is a schematic sectional view of a loading variant comprising removable tools according to the invention.

[0054] [Fig. 3] Figure 3 is a simplified schematic view of an installation according to the invention.

[0055] [Fig. 4] Figure 4 is a schematic sectional view of a CVI furnace of the installation according to the invention comprising a load.

[0056] Description of the embodiments

[0057] The present invention applies to the manufacture of parts made of composite material and in particular of the SiC / SiC or C / SiC type. More particularly, the invention finds an advantageous application during the consolidation or densification by chemical infiltration in the gas phase of fibrous preforms.

[0058] Figure 1 schematically illustrates an example of loading comprising a removable tool 100 accommodating several fiber preforms 5 arranged in shapers 7.

[0059] The removable tool 100 comprises a homogenization chamber 110 for the gas(es), which has at least one gas inlet orifice 111. The homogenization chamber 110 is delimited by a first perforated plate 115, on the side of the chamber opposite the gas inlet orifice(s) 111. The homogenization chamber 110 is configured to homogenize the temperature and the composition of the gas(es) entering said chamber 110 through the gas inlet orifice(s) 111.

[0060] The removable tool 100 also comprises a depletion chamber 130 for the gas(es), within which the reactive species of the gas(es) are finished being consumed, which has at least one gas outlet orifice 131. The depletion chamber 130 is delimited by a second perforated plate 125, on the side of the chamber opposite the gas outlet orifice(s) 131. The depletion chamber 130 is configured to deplete the reactive gas(es) in order to avoid the deposition of condensable species at the outlet of the removable tool 100.

[0061] The removable tool 100 further comprises a reaction chamber 120 extending between the first perforated plate 115 and the second perforated plate 125. Thus, the homogenization chamber 110 and the depletion chamber 130 are arranged on either side of the reaction chamber 120. The reaction chamber 120 is configured to receive at least one fiber preform 5, which may or may not be arranged in a former 7. The perforations of the first plate 115 are arranged so as to allow a sufficient supply of gas to the fiber preform(s) 5 present in the reaction chamber 120, in particular when the fiber preform(s) 5 are held by one or more formers 7.

[0062] The former(s) 7 may for example be multi-perforated formers. Such formers are described in particular in documents FR 3 021 671 A1 or FR 3 059 679 A1. The former(s) may also comprise a shaping housing having non-perforated interior surfaces, but provided with grooves or holding elements on which the fiber preform arranged in the shaping housing can rest. A gas inlet located at one end of the shaping housing allows gas to enter the interior of the former, which can then circulate in contact with the fiber preform in the grooves or between the holding elements. The gas is then evacuated through a gas outlet located at the other end of the shaping housing. Such a former is for example described in document FR 3 107 283.

[0063] According to a particular embodiment of the invention, figure 2 schematically illustrates an example of loading comprising a removable tool 200 receiving several fiber preforms 6 arranged in a single multiple conformer 8, this loading having a particularly advantageous configuration for large-scale manufacturing.

[0064] As previously, the removable tool 200 comprises a homogenization chamber 210 for the gas(es), which has at least one gas inlet orifice 211. The homogenization chamber 210 is delimited by a first perforated plate 215, on the side of the chamber opposite the gas inlet orifice(s) 211. The removable tool 200 also comprises a depletion chamber 230 for the gas(es), which has at least one gas outlet orifice 231. The depletion chamber 230 is delimited by a second perforated plate 225, on the side of the chamber opposite the gas outlet orifice(s) 231.

[0065] The reaction chamber 220 of the removable tool 200 extends between the first perforated plate 215 and the second perforated plate 225. A large part of the volume of the reaction chamber 220 is occupied by a multiple former 8 comprising a plurality of shaping housings 80, each shaping housing 80 being configured to accommodate a fiber preform 6. Thus, the number of fiber preforms that can be loaded into the removable tool is greatly increased.

[0066] The conformer 8 illustrated in FIG. 2 comprises, by way of example, four shaping housings 80. It is of course not outside the scope of the invention if the conformer comprises two, three or more than four shaping housings.

[0067] Each shaping housing 80 is formed by a first surface 81 and a second surface 82 facing the first surface 81. In the configuration shown in FIG. 2, the shaper 8 is in the form of a structural enclosure comprising a start plate, three intermediate plates and an end plate. The intermediate plates separate and delimit the shaping housings 80 from each other. The start and end plates make it possible to close the shaping housings 80 located at the ends of the shaper 8. The fiber preforms 6 are interposed in the shaping housings 80 between the start plate, the intermediate plates and the end plate.

[0068] Thus, the first surface 81 of each shaping housing 80 belongs to the start plate or to an intermediate plate. The second surface 82 of each shaping housing 80 belongs to an intermediate plate or to the end plate. Each intermediate plate thus comprises the first surface 81 of a housing 80 and the second surface 82 of an adjacent housing 80.

[0069] Each shaping housing 80 extends along its first surface 81 and its second surface 82 between a first end and a second end. Each shaping housing 80 comprises at least one gas inlet 80e positioned at the first end of said shaping housing 80, and opening into the shaping housing 80 between the first surface 81 and the second surface 82 of said housing 80. Each shaping housing 80 further comprises at least one gas outlet 80s positioned at the second end of said shaping housing 80, and opening into the shaping housing 80 between the first surface 81 and the second surface 82 of said housing 80.

[0070] Preferably, the first ends of all the shaping housings 80 are located on one side of the shaper 8 and the second ends of all the shaping housings 80 are located on another side of said shaper 8. Thus, preferably, the gas inlets 80e of the shaper 8 are all located on the same side, and the gas outlets 80s of the shaper 8 are all located on the same side, opposite that of the gas inlets 80e. This makes it easier to arrange the shaper 8 in the removable tool 200, and any connections of the gas inlets and outlets. The perforations of the first perforated plate 215 are adapted to the gas inlets 80e of the shaper 8. Preferably, as illustrated in FIG. 2, the perforations of the first perforated plate 215 coincide with the gas inlets 80e of the shaper 8.Thus, when the shaper 8 is arranged in the removable tool 200, the gas inlets 80e of the shaper 8 are located in the extension of the perforations of the first perforated plate 215.

[0071] The perforations of the second perforated plate 225 are adapted to the gas outlets 80s of the shaper 8. Preferably, as illustrated in FIG. 2, the perforations of the second perforated plate 225 coincide with the gas outlets 80s of the shaper 8. Thus, when the shaper 8 is arranged in the removable tool 200, the gas outlets 80s of the shaper 8 are located in the extension of the perforations of the second perforated plate 225.

[0072] By using a single former 8 rather than a plurality of formers 7, it is possible to load more fiber preforms into the removable tool 200. Furthermore, the use of such a former 8 makes it possible to reduce the quantity of reactive gas required, the reactive gas(es) circulating in the reaction chamber 220 being immediately in contact with the fiber preforms 6. The loading illustrated in FIG. 2 is therefore particularly economical and suitable for large-scale production.

[0073] According to a particular embodiment of the invention illustrated in Figure 2, when a fiber preform 6 is arranged in a shaping housing 80 of the shaper 8, the gas inlet(s) 80e of the housing 80 are located only between the first surface 81 of said housing and the preform 6, at the first end of the shaping housing 80. Furthermore, the gas outlet(s) 80s of the housing 80 are located only between the second surface 82 of said housing and the preform 6, at the second end of the housing 80. It is of course possible to reverse the role of the first surface of the housing and the second surface of the housing without departing from this embodiment.

[0074] According to another particular embodiment of the invention, when a fiber preform is arranged in a shaping housing of the shaper, the gas inlet(s) of the shaping housing may be located both between the first surface of the housing and the preform, and between the second surface of the housing and the preform, at the first end of the shaping housing. Furthermore, the gas outlet(s) of the shaping housing may be located both between the first surface of the housing and the preform, and between the second surface of the housing and the preform, at the second end of the shaping housing.

[0075] Each first or second surface 81, 82 of each shaping housing 80 has holding elements 81a, 82a projecting relative to said surface.

[0076] 81, 82. These holding elements 81a, 82a may take the form of protrusions or reliefs extending from the first or second surface 81, 82 towards the opposite surface. These holding elements 81a, 82a thus extend to an end face, intended to be in contact with the fiber preform 6 arranged in the shaping housing 80.

[0077] When a fiber preform 6 is arranged in a shaping housing 80 of the shaper 8, the holding elements 81a, 82a of the shaping housing 80 extend between the fiber preform 6 and the first or second surface 81,

[0078] 82. Gas can thus circulate between the fiber preform 6 and the first or second surface 81, 82 of the shaping housing 80 during the consolidation or densification step.

[0079] At least some of the surface holding elements may have a frustoconical shape, and preferably a frustoconical shape of revolution. At least some of the surface holding elements may have a cylindrical shape, and preferably a cylindrical shape of revolution, as is the case in the example illustrated in Figure 2. At least some of the surface holding elements may have a polyhedron shape, preferably having two trapezoid-shaped faces, or even four trapezoid-shaped faces distinct from the end face. The holding elements may take the form of grooves defining flow channels for the reactive gas.

[0080] Preferably, at least a portion of the holding elements has a section that gradually decreases from their junction with the first or second surface to their end face. Such a progressive reduction in the section of the holding elements along their direction of extension makes it possible to give them greater robustness, while obtaining an end face with the smallest possible area for contact with the fiber preform.

[0081] Preferably, the sum of the areas of the end faces of the holding elements of the first or second surface is less than or equal to 50% of the total area of ​​said surface, in order to expose the largest possible surface of the fiber preform 5 to the reactive gas. Preferably, the sum of the areas of the end faces of the holding elements of the first or second surface is less than or equal to 40% of the total area of ​​said surface, and preferably greater than or equal to 5% of the total area of ​​said surface.

[0082] Preferably, the area of ​​the end face of at least a portion of the holding elements is between 1 mm 2 and 50 mm 2 . Preferably, the area of ​​the end face of at least a portion of the holding elements is between 2.5 mm 2 and 15 mm 2 .

[0083] According to another embodiment of the invention, the contact between at least a portion of the holding elements and the fiber preforms is said to be point contact, that is to say that the end face area of ​​at least a portion of the holding elements is less than 1 mm 2 . At least a portion of the holding elements may have, for example, an overall shape of a needle, a straight rod, a rod curved into an arc or a “C” shape.

[0084] It is of course not outside the scope of the invention if the holding elements have another shape or geometry, other dimensions, or a distribution different from those described in the present example. In particular, the holding elements can form various groupings between two surfaces, or even within the same surface.

[0085] Preferably, the removable tool 100 or 200 is made of graphite. According to a particular embodiment of the invention, the removable tool 100 or 200 is made of a conductive material capable of withstanding the conditions imposed for densification or consolidation by chemical infiltration in the gas phase, such as for example graphite, and the removable tool 100 or 200 is provided with electrical connection terminals 150 or 250. Thus, the removable tool 100 or 200 can act as a resistor and can therefore heat the fiber preform(s) 5 or 6 present in the reaction chamber 120 or 220 as well as the gases present in the removable tool 100 or 200.

[0086] Each fiber preform 5 or 6 arranged in the removable tool 100 or 200 corresponds to a “dry” fiber texture, i.e. not impregnated with a resin or the like. Each fiber preform 5 or 6 may comprise a plurality of threads of various types, in particular ceramic or carbon threads or a mixture of such threads. Preferably, each fiber preform 5 or 6 may be made from silicon carbide fibers. Generally, each fiber preform 5 or 6 may also be made from fibers made of the following materials: alumina, mullite, silica, an aluminosilicate, a borosilicate, carbon, or a mixture of several of these materials.

[0087] Each fiber preform 5 or 6 can be obtained from at least one textile operation using ceramic and / or carbon yarns. Each preform 5 or 6 can be made by stacking layers or plies obtained by two-dimensional (2D) weaving. By "two-dimensional weaving" is meant here a conventional weaving method by which each weft yarn passes from one side to the other of yarns of a single warp layer or vice versa.

[0088] Each fiber preform 5 or 6 can, in particular, be obtained by multi-layer or three-dimensional weaving of the threads. By "three-dimensional weaving" or "3D weaving" is meant a weaving method by which at least some of the warp threads bind weft threads over several weft layers. A reversal of roles between warp and weft is possible.

[0089] Each fiber preform 5 or 6 can also be made from unidirectional fiber (UD) sheets which can be obtained by automatic fiber placement (AFP for “Automated Fiber Placement”), or by linear winding.

[0090] It is also possible to start from fiber textures such as two-dimensional fabrics or unidirectional (UD) sheets, and to obtain each fiber preform 5 or 6 by draping such fiber textures on a form. These textures can optionally be linked together for example by sewing, by implantation of threads or rigid elements, or by needling to form the fiber preform 5 or 6.

[0091] Figure 3 schematically illustrates a gas phase consolidation or densification installation 1 comprising a plurality of modules 10, 20 and 30. Each module corresponds to a CVI furnace 10, to a preheating furnace 20 or to a cooling enclosure 30.

[0092] The removable tool 100 or 200 is configured to be arranged in a module 10, 20, 30 of the gas phase consolidation or densification installation 1, and in particular in a furnace 10, 20. Preferably, the removable tool 100 or 200 is configured to be arranged in each of the modules 10, 20, 30 of the installation 1, and consequently in each of the furnaces 10, 20 of the installation 1. Preferably, the removable tool 100 or 200 is arranged in a module 10, 20, 30 of the installation 1 by means of a door 10a, 20a, 30a belonging to said module 10, 20, 30.

[0093] As illustrated in Figure 3, the modules 10, 20, 30 may also comprise at least one other door 10b, 20b, 30b, making it possible to facilitate maintenance operations, or to remove the removable tools through a door other than the one through which they were loaded.

[0094] Preferably, the installation 1 comprises several removable tools 100 or 200. Thus, when a removable tool 100 or 200 must be cleaned and prepared for a next cycle, one or more other removable tools 100 or 200 can be used to be able to continue to densify or consolidate preforms 5 or 6. Consequently, the recurring steps of cleaning the densification or consolidation tool 100 or 200 can be carried out while the oven(s) 10 are operating to consolidate or densify other parts.

[0095] In order to be able to move the removable tool 100 or 200 from one module 10, 20, 30 to another, the installation 1 may comprise one or more transfer tunnels 50 specially adapted to said removable tool 100 or 200. Each transfer tunnel 50 comprises at least a first opening and a second opening, each opening being configured to create a sealed contact between the door 10a, 20b, 30a of a module 10, 20, 30 of the installation 1 and said transfer tunnel 50. Thus, each transfer tunnel 50 makes it possible to create a passage between at least two modules 10, 20, 30 of the installation 1, the passage preferably being gas-tight.

[0096] Preferably, the transfer tunnel 50 is made at least partially of an adiabatic material, i.e. limiting the heat exchanges between the outside and the inside of the tunnel 50. It is thus, for example, possible to transfer removable tools 100 or 200 from one module 10, 20, 30 to the other with limited heat loss. The transfer tunnel(s) 50 may be fixed between at least two modules 10, 20, 30. The transfer tunnel(s) 50 may also be removable and may be moved so as to join different modules 10, 20, 30 as required. In the example illustrated in FIG. 3, the installation 1 comprises only one fixed transfer tunnel 50, which connects all the modules 10, 20, 30 of the installation 1.

[0097] As illustrated in Figure 3, the installation 1 comprises at least one CVI furnace 10 for consolidation or densification by gas infiltration. Preferably, the installation 1 comprises at least two CVI furnaces 10 for consolidation or densification by gas infiltration. The use of several CVI furnaces 10 makes it possible to use different gases or gas mixtures, and to have greater flexibility for implementing the processes.

[0098] Figure 4 illustrates an example of a CVI furnace 10, in which a load comprising a removable tool 100 and at least one fiber preform 5 is arranged. Each CVI furnace 10 comprises at least one gas injector 11, preferably in the form of a graphite tube. When the removable tool 100 is arranged in a CVI furnace 10, the gas inlet orifice(s) 111 of the removable tool 100 are placed in the extension of the gas injector(s) 11 of said furnace 10. Preferably, the connection between the gas inlet orifice(s) 111 of the removable tool 100 and the gas injector(s) 11 of said furnace 10 is sealed. Thus, the escape of reactive gases into the enclosure of the furnace 10, outside the removable tooling 100, is limited. The fouling of the furnace 10 is therefore greatly limited, making it possible to considerably reduce the duration and frequency of maintenance and cleaning operations of the CVI furnace 10.

[0099] Each CVI furnace 10 may further comprise an ejection cone 13 connected to a pumping system 12. When the removable tool 100 is arranged in a CVI furnace 10, the gas outlet orifice(s) 131 of the removable tool 100 are placed opposite the ejection cone 13 of said furnace 10. Preferably, each CVI furnace 10 comprises a chimney 14 making it possible to suck in the gas leaving the removable tool 100 as close as possible to the gas outlet orifice(s) 131 of the removable tool 100. This chimney 14 may be retractable, i.e. retractable. Thus, the chimney 14 can be retracted in order to facilitate the loading and unloading operations of the removable tool 100, and deployed during operation of the CVI furnace 10. Such a chimney 14 thus makes it possible to further limit or even eliminate the circulation of reactive gases in the enclosure of the furnace 10, even when depleted, further reducing the fouling of the furnace 10.

[0100] According to a particular embodiment of the invention, an inert gas, for example nitrogen, can circulate in the enclosure of the CVI furnace 10 outside the removable tool 100, in order to limit back-diffusion of the reactive or produced species towards any heating walls of the CVI furnace 10.

[0101] According to another particular embodiment of the invention, in which the removable tooling 100 comprises electrical connection terminals 150, each CVI furnace 10 may comprise electrical connection terminals 15. When the removable tooling 100 is arranged in such a CVI furnace 10, the electrical connection terminals 150 of the removable tooling 100 may be connected to the electrical connection terminals 15 of the CVI furnace 10. Thus, the removable tooling 100 may act as a resistor and may therefore heat the fiber preform(s) 5 present in the reaction chamber 120 as well as the gases present in the removable tooling 100. In this particular embodiment of the invention, it is therefore not necessary for the CVI furnace 10 to be capable of heating. The CVI furnace 10 then fulfills a thermal insulation function.

[0102] As illustrated in Figure 3, the installation 1 preferably comprises at least one preheating furnace 20, making it possible to heat the removable tooling 100. Thus, the presence of a preheating furnace 20 makes it possible to simply raise the temperature of the fiber preforms 5 and possibly the gas(es) present in the removable tooling 100 before their consolidation or densification, without requiring the use of a CVI furnace 10. Thus, the operation of raising the temperature of the fiber preforms 5 and possibly the gas(es) does not block a CVI furnace 10, which can remain dedicated to consolidation or densification. The preheating furnace 20 can thus have a simpler configuration than the CVI furnace(s) 10, because it does not require a gas injector, a pumping system or a gas evacuation system.

[0103] According to a particular embodiment of the invention, in which the removable tool 100 comprises electrical connection terminals 150, each preheating furnace 20 may comprise electrical connection terminals. When the removable tool 100 is arranged in such a preheating furnace 20, the electrical connection terminals 150 of the removable tool 100 may be connected to the electrical connection terminals of the preheating furnace 20. Thus, the removable tool 100 may act as a resistor and may therefore heat the fiber preform(s) 5 present in the reaction chamber 120 and possibly the air present in the removable tool 100. In this particular embodiment of the invention, it is therefore not necessary for the preheating furnace 20 to be capable of heating. The preheating furnace 20 then fulfills a thermal insulation function.

[0104] As illustrated in Figure 3, the installation 1 preferably comprises at least one cooling cell 30, making it possible to cool the removable tool 100 preferably in an accelerated manner. Thus, the presence of a cooling cell 30 makes it possible to simply cool the densified or consolidated parts and possibly the gas(es), without requiring the occupation and cooling of a CVI furnace 10. Thus, the operation of cooling the densified or consolidated parts does not block a CVI furnace 10, which can remain dedicated to consolidation or densification.

[0105] The cooling cell 30 can also allow a removable tool 100 to be loaded before it is transferred into the preheating furnace 20 or into a CVI furnace 10 via the transfer tunnel 50. By doing so, the heat losses from the preheating furnace 20 or the CVI furnace 10 are limited compared to if said preheating furnace 20 or CVI furnace 10 were directly open to the outside. The cooling cell 30 can also allow the oxygen present in the removable tool 100 to be evacuated before it enters the rest of the installation 1.

[0106] We will now describe an example of a manufacturing process for at least one part made of composite material, in relation to installation example 1 illustrated in Figure 3.

[0107] According to a first step of the method of the invention, the loading is prepared. Thus, at least one fiber preform 5 or 6 as defined above is loaded into the reaction chamber 120 or 220 of a removable tool 100 or 200 according to the invention. The fiber preform(s) 5 or 6 may be loaded alone, or held in one or more formers 7 or 8. The fiber preform(s) 5 or 6 are arranged in the reaction chamber 120 or 220, with or without former 7 or 8, so that the perforations of the first and second plates 115, 215 and 125, 225 allow the passage of the gas(es) into the fiber preform 5 or 6.

[0108] According to a second step of the method of the invention, a preheating step is carried out. The removable tool 100 or 200 can be placed in a preheating furnace 20 via a door 20a belonging to the preheating furnace 20, in order to bring it to the desired temperature. Preferably, the removable tool 100 or 200 is previously placed in the cooling cell 30, where any oxygen present in the removable tool 100 or 200 can be evacuated, before being transferred to the preheating furnace 20 via a door 20b thanks to the transfer tunnel 50. Indeed, the opening of the preheating furnace 20 via the door 20a which opens onto the outside of the installation 1 can cause significant heat losses.

[0109] If the removable tool 100 or 200 comprises electrical connection terminals 150 or 250 and if the preheating furnace 20 comprises electrical connection terminals, the terminals 150 or 250 of the removable tool 100 or 200 can be connected to the terminals of the preheating furnace 20. The removable tool 100 can then heat the fiber preform(s) 5 or 6 and possibly the air present in the removable tool 100 or 200, the preheating furnace 20 can also heat or only perform a thermal insulation function. The removable tool 100 or 200 can also be brought to a desired pressure.

[0110] When the removable tool 100 or 200 has reached the desired temperature and possibly the desired pressure, it is unloaded from the preheating furnace 20 to be loaded into a CVI furnace 10. The transfer of the removable tool 100 or 200 from the preheating furnace 20 to the CVI furnace 10 can be carried out by means of a transfer tunnel, fixed or removable. The transfer tunnel 50 is arranged so as to form a sealed contact between a door 20b of the preheating furnace 20, preferably separate from the door 20a through which the removable tool 100 or 200 had been loaded, and said tunnel. Similarly, the transfer tunnel 50 is arranged so as to form a sealed contact between a door 10a of the CVI furnace 10, preferably separate from the door 10b through which the maintenance and preparation operations of the CVI furnace 10 are carried out, and said tunnel.Thus, the removable tooling 100 or 200 can be transferred from the preheating furnace 20 to the CVI furnace 10 via the transfer tunnel 50 while limiting temperature and pressure losses as much as possible.

[0111] The removable tooling 100 or 200 may not be preheated in a preheating oven 20, to be loaded directly into a CVI oven 10. In this case, this preliminary heating step is carried out directly in the CVI oven 10. If the removable tooling 100 or 200 comprises electrical connection terminals 150 or 250 and if the CVI oven 10 comprises electrical connection terminals 15, the terminals 150 or 250 of the removable tooling 100 or 200 can be connected to the terminals 15 of the CVI oven 10. The removable tooling 100 or 200 can then heat the fiber preform(s) 5 or 6 and possibly the air present in the removable tooling 100 or 200, the CVI oven 10 being able to also heat or only fulfill a thermal insulation function during this preliminary heating step. The removable tool 100 or 200 can also be brought to a desired pressure.According to a third step of the method of the invention, the fiber preform(s) 5 or 6 are consolidated or densified. The removable tool 100 or 200 has thus been loaded into a CVI furnace 10. The removable tool 100 or 200 is arranged in the CVI furnace 10 so that the gas inlet orifice(s) 111 or 211 of the removable tool 100 or 200 are placed in the extension of the gas injector(s) 11 of said furnace 10. Preferably, the connection between the gas inlet orifice(s) 111 or 211 of the removable tool 100 or 200 and the gas injector(s) 11 of said furnace 10 is sealed. Furthermore, the removable tool 100 or 200 is arranged in the CVI furnace 10 so that the gas outlet orifice(s) 131 or 231 of the removable tool 100 or 200 are placed opposite the ejection cone 13 of said furnace 10.If the CVI furnace 10 comprises a retractable chimney 14, the latter is deployed as close as possible to the gas outlet orifice(s) 131 or 231 of the removable tooling 100 or 200, preferably so as to form a sealed contact around the gas outlet orifice(s) 131 or 231. Such an installation makes it possible to greatly limit, or even prevent, the circulation of reactive gases - even depleted ones - in the CVI furnace 10. The fouling of the CVI furnace 10 is therefore very reduced, and the CVI furnace 10 can therefore be used for longer periods without requiring cleaning or maintenance operations.

[0112] If the removable tooling 100 or 200 comprises electrical connection terminals 150 or 250 and if the CVI furnace 10 comprises electrical connection terminals 15, the terminals 150 or 250 of the removable tooling 100 or 200 can be connected to the terminals 15 of the CVI furnace 10. The removable tooling 100 or 200 can then heat the fiber preform(s) 5 or 6 and possibly the reactive gas(es) present in the removable tooling 100 or 200, the CVI furnace 10 also being able to heat or only perform a thermal insulation function during the consolidation or densification step. The removable tooling 100 or 200 can also be brought to a desired pressure.

[0113] One or more reactive gases containing one or more precursors of the matrix material to be deposited are injected by the gas injector(s) 11 of the CVI furnace 10 and introduced into the homogenization chamber 130 or 230 of the removable tool 100 or 200 via the gas inlet orifice(s) 111 or 211 of said tool 100 or 200. In the case of a ceramic material, such as silicon carbide (SiC), methyltrichlorosilane (MTS) may be used in a manner well known per se as a silicon carbide (SiC) precursor. In the case of carbon, for example, gaseous hydrocarbon compounds are used, typically propane, methane or a mixture of the two.

[0114] The temperature, pressure and composition of the reactive gas(es) is(are) homogenized in the homogenization chamber 130 or 230 of the removable tool 100 or 200. Then, the homogenized reactive gas(es) enter the reaction chamber 120 or 220 of the removable tool 100 or 200 via the perforations present in the first perforated plate 115 or 215.

[0115] The consolidation or densification of each fiber preform 5 or 6 is ensured, in a manner well known per se, by depositing within it the matrix material produced by decomposition of the precursor(s) contained in the reactive gas(es) diffusing inside the accessible internal porosity of each preform 5 or 6.

[0116] The reactive gas(es) then enter the depletion chamber 130 or 230 of the removable tool 100 or 200 via the perforations present in the second perforated plate 125 or 225, where they are depleted and where the reactive chemical species present in said gases are finally consumed.

[0117] Finally, the depleted reactive gas(es) are drawn through the gas outlet(s) 131 or 231 to the ejection cone 13 of the CVI furnace 10, preferably via the retractable chimney 14.

[0118] According to a fourth step of the method of the invention, the removable tool 100 or 200 is cooled. Preferably, the cooling of the removable tool 100 or 200 is carried out in a cooling cell 30 of the installation 1. The removable tool 100 or 200 is then unloaded from the CVI furnace 10 via the door 10a belonging to the CVI furnace 10. The transfer of the removable tool 100 or 200 from the CVI furnace 10 to the cooling cell 30 can be carried out via a transfer tunnel, fixed or removable. The transfer tunnel 50 is arranged so as to form a sealed contact between a door 10a of the CVI furnace 10, preferably separate from the door 10b through which the maintenance and preparation operations of the CVI furnace 10 are carried out, and said tunnel.Likewise, the transfer tunnel 50 is arranged so as to form a sealed contact between a door 30a of the cooling cell 30, preferably separate from the door 30b through which the removable tool 100 or 200 will be unloaded from said cell 30, and said tunnel.

[0119] The removable tooling 100 or 200 may not be cooled outside a CVI 10 furnace, but may be cooled inside the CVI 10 furnace.

[0120] According to a fifth step of the method of the invention, the consolidated or densified parts are removed. Thus, the cooled removable tool 100 or 200 is removed from the cooling cell 30, or from the CVI furnace 10, then the consolidated or densified part(s) are removed from the removable tool 100 or 200.

[0121] The installation 1 according to the invention can also make it possible to consolidate and then densify fibrous preforms, by carrying out these two operations in the CVI 10 furnaces of the installation 1. In the case where a fibrous preform is consolidated by the installation 1 according to the invention, it can then be densified by gaseous, liquid or solid means in a well-known manner.

[0122] The installation according to the invention makes it possible to densify fiber preforms by gaseous means. The installation according to the invention thus makes it possible to form parts made of composite material, in particular ceramic matrix composites (CMC) such as SiC / SiC or C / SiC composites. The removable tooling and the installation according to the invention thus make it possible in particular, but not exclusively, to produce parts made of composite material having excellent mechanical properties at high temperature and in an oxidizing environment, such as for example aeronautical engine parts.

Claims

Demands

1. Installation (1) for consolidation or densification by gas-phase chemical infiltration comprising: - at least one removable tooling (100; 200) for the consolidation or densification in the gas phase of at least one fibrous preform (5; 6), the removable tooling (100; 200) being configured to be placed in a furnace (10, 20), the removable tooling (100; 200) comprising a homogenization chamber (110; 210) comprising at least one gas inlet port (111; 211) and a depletion chamber (130; 230) comprising at least one gas outlet port (131; 231), the removable tooling (100; 200) further comprising a reaction chamber (120; 220) disposed between the homogenization chamber (110; 210) and the depletion chamber (130; 230) and configured to receive at least one fibrous preform (5; 6), the reaction chamber (120; 220) being separated from the homogenization (110; 210) and depletion (130; 230) chambers by perforated plates (115, 125), and - at least one CVI furnace (10) comprising at least one gas injector (11) and a gas evacuation system (13, 14), the CVI furnace (10) being suitable for receiving the removable tooling (100) such that at least one gas inlet port (111) of the removable tooling (100) is connected to at least one gas injector (11) of the CVI furnace (10), the CVI furnace (10) being configured to heat or thermally insulate said removable tooling (100), the installation being characterized in that it further comprises: - at least one preheating oven (20) capable of receiving removable tooling (100) and configured to preheat or thermally insulate said removable tooling (100), and - at least one cooling cell (30) suitable for receiving removable tooling (100) and configured to cool said removable tooling (100).

2. Installation (1) according to claim 1, wherein the removable tooling (100; 200) is made at least partially of conductive material and includes electrical connection terminals (150; 250). Tl

3. Installation (1) according to claim 1 or 2, wherein the removable tooling (100; 200) is made of graphite.

4. Installation (1) according to any one of claims 1 to 3, said installation (1) further comprising at least one transfer tunnel (50) configured to permit the movement of removable tooling (100) at least between the CVI furnace (10) and another CVI furnace (10), a preheating furnace (20) or a cooling cell (30).

5. Use of an installation (1) for consolidation or densification by gas-phase chemical infiltration comprising at least one CVI furnace (10), a preheating furnace (20) and a cooling cell (30), the CVI furnace (10) comprising at least one gas injector (11) and a gas evacuation system (13, 14), the use comprising: - the placement of a load in the preheating furnace (20), the load comprising removable tooling (100; 200) for the consolidation or densification in the gas phase of at least one fibrous preform (5; 6), the removable tooling (100; 200) comprising a homogenization chamber (100; 200) comprising at least one gas inlet orifice (111; 211) and a depletion chamber (130; 230) comprising at least one gas outlet orifice (131; 231), the removable tooling (100; 200) further comprising a reaction chamber (120; 220) disposed between the homogenization chamber (110; 210) and the depletion chamber (130; 230), the reaction chamber (120; 220) being separated from the homogenization chambers (110; 210) and depletion chambers (130; 230) by perforated plates (115, 125), the loading further comprising at least one fibrous preform (5; 6) disposed in the reaction chamber (120; 220) of the removable tooling (100; 200), and - the preheating of said load, then - placing the load in the CVI furnace (10) so that at least one gas inlet port (111) of the removable tooling (100) of the load is connected to at least one gas injector (11) of the CVI furnace (10), then consolidation or densification by gas-phase infiltration of a matrix of the fibrous preform(s) (5) present in the load, then - the placement of the load in the cooling cell (30), and the cooling of said load, then - the removal of the load from the cooling cell (30).

6. Use according to claim 5, wherein the loading further comprises at least one conformer (7; 8) in which the fibrous preform (5; 6) is held, the conformer (7; 8) being disposed in the reaction chamber (120; 220) of the removable tooling (100; 200).

7. Use according to claim 6, wherein said at least one conformer (8) comprises a plurality of conforming housings (80), each conforming housing (80) being formed by a first surface (81) and a second surface (82) facing each other and being intended to accommodate a fibrous preform (6), each first or second surface (81, 82) comprising retaining elements (81a, 82a) projecting from said surface and extending to an end face intended to be in contact with the fibrous preform (6), each conforming housing (80) extending between at least one gas inlet (80e) and at least one gas outlet (80s) positioned between the first surface (81) and the second surface (82) of said housing (80).

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