Manufacturing a fibrous preform from a rigidified fibrous texture

Abstract

Manufacturing a fibrous preform from a stiffened fibrous texture. The invention relates to a method for manufacturing a fibrous preform (600) intended to form the fibrous reinforcement of a part made of composite material, comprising: - (1000) the creation of a fibrous texture (200) by weaving, - (3000) the cutting of the fibrous texture (200) so as to obtain one or more fibrous blanks (400), - (4000) the shaping of the fibrous blank(s) (400) so as to obtain a fibrous preform (600), the method being characterized in that the fibrous texture (200) is stiffened by a hardened thermoplastic resin before cutting said fibrous texture (200), the thermoplastic resin being removed after cutting the stiffened fibrous texture (300) or after shaping the fibrous blank(s) (400). Figure for the abstract: Fig. 5

Description

Title of the invention: Fabrication of a fibrous preform from a rigidified fibrous texture technical field

[0001] The present invention relates to the manufacture of parts made of composite material, and more particularly of parts made of composite material in which at least part of the fibrous reinforcement is formed by a fibrous preform. Previous technique

[0002] To obtain lightweight turbomachine parts with excellent thermomechanical properties, composite materials are commonly used. The use of composite materials helps optimize turbomachine performance, particularly by reducing the overall mass of the turbomachine, which contributes to lower fuel consumption and therefore a significant reduction in pollutant emissions. Furthermore, due to their superior resistance to high temperatures, ceramic matrix composite materials require less cooling. Since this cooling is traditionally drawn from the compressor, which impacts the turbomachine's efficiency, composite materials allow for further improvements in engine efficiency and a greater reduction in fuel consumption.

[0003] In particular, it is known to produce a fibrous texture by weaving, for example on a Jacquard loom. The fibrous texture coming off the loom is then cut to obtain a fibrous blank. Then, one or more fibrous blanks are shaped to produce a fibrous preform, said fibrous preform being intended to form the fibrous reinforcement of the composite part to be obtained. The fibrous preform is then densified by a matrix to obtain the desired composite part. Such a process is, for example, described in document WO 2023 / 007073 AL

[0004] However, it has been observed that cutting the fibrous texture to obtain a fibrous blank can be inaccurate. Furthermore, it has been observed that positioning the fibrous blank(s) in a mold to shape the fibrous preform exhibits poor repeatability and is difficult to automate. Thus, the cutting and shaping steps can generate non-conformities, and industrializing such a process in its current state is laborious. Description of the invention

[0005] The present invention aims to provide a manufacturing process that allows a conforming fibrous preform to be positioned and produced easily and repeatably.

[0006] To this end, the invention proposes a method for manufacturing a fibrous preform intended to form the fibrous reinforcement of a part made of composite material comprising:

[0007] - the creation of at least one fibrous texture by weaving between a plurality of yarns of warp and a plurality of weft threads,

[0008] - cutting said at least one fibrous texture so as to obtain a or several fibrous rudiments,

[0009] - shaping the fibrous blank(s) so as to obtain a preform fibrous,

[0010] the process being characterized in that said at least one fibrous texture is impregnated with a thermoplastic resin and in that said resin is hardened before cutting said at least one fibrous texture, so that the cutting is carried out on a rigidified fibrous texture, the thermoplastic resin being removed after cutting the rigidified fibrous texture or after shaping the fibrous blank(s).

[0011] Thus, since the cutting is performed on a rigidified fibrous texture, it is more precise. Indeed, because the fibrous texture is held in place by the hardened resin, it does not deform under the action of the cutting device. Furthermore, the rigidified fibrous texture is easier to handle and position than a flexible fibrous texture, particularly for an automated machine.

[0012] According to a particular embodiment of the invention, the thermoplastic resin is removed after shaping the fibrous blank(s).

[0013] When shaping is carried out with one or more fibrous blanks stiffened by hardened resin, the shaping process is facilitated. For example, a stiffened fibrous blank is easier to position in a mold with correct and repeatable placement. Furthermore, the stiffened blank presents less risk of non-conformity during shaping. The risks of non-conformities are thus reduced. In addition, a stiffened fibrous blank is easier to handle than a flexible fibrous blank, particularly for an automated machine.

[0014] According to a particular embodiment of the invention, during the shaping step of the fibrous blank(s), the fibrous blank(s) are heated to a softening temperature of the thermoplastic resin.

[0015] Thus, the fibrous blank(s) are less rigid and can be deformed more easily to obtain the desired shape. The entire fibrous blank(s) can be heated so that all the resin is softened.

[0016] According to a particular embodiment of the invention, during the shaping step the fibrous blank(s) are heated locally so that at least part of the thermoplastic resin remains hardened.

[0017] Thus, only the portion(s) of the fibrous blank(s) to be shaped are heated. It is therefore unnecessary to heat the portion(s) of the fibrous blank(s) that will not be shaped. Consequently, not all of the resin is softened. The heating step is thus simplified and more economical.

[0018] According to a particular embodiment of the invention, the shaping of the fibrous blank(s) is carried out in a mold.

[0019] As indicated above, the process as described previously is particularly interesting when it is necessary to position one or more fibrous blanks in a mold according to a very specific positioning.

[0020] According to a first particular embodiment of the invention, the shaping step of the fibrous blank(s) is carried out in a first shaping mold and the thermoplastic resin removal step is carried out while the fibrous preform is placed in a second mold different from the first mold.

[0021] According to a second particular embodiment of the invention, the shaping step of the fibrous blank(s) and the thermoplastic resin removal step are carried out in the same mold configured for the consolidation or densification of the fibrous preform.

[0022] According to a particular embodiment of the invention, the hardened thermoplastic resin is transparent or translucent.

[0023] Thus, if the fibrous texture or the fibrous blank includes tracer or marker wires on the surface, the resin does not prevent their identification. Consequently, the process as described above can be used in combination with tracer or marker wires to further improve its accuracy and repeatability.

[0024] According to a particular embodiment of the invention, the thermoplastic resin comprises polyvinyl alcohol (PVA).

[0025] Such a resin has the dual advantage of being transparent and easy to remove. In particular, such a resin may be an aqueous solution comprising polyvinyl alcohol.

[0026] According to a particular embodiment of the invention, the thermoplastic resin comprises poly(2-ethyl-2-oxazoline).

[0027] Indeed, such a polymer has the advantage of being soluble in water and can be thermally debound. Such a resin is also transparent.

[0028] The thermoplastic resin may comprise several different polymers. For example, the thermoplastic resin may comprise polyvinyl alcohol (PVA) and poly(2-ethyl-2-oxazoline).

[0029] The invention further proposes a method for manufacturing a part made of composite material comprising:

[0030] - the manufacture of a fibrous preform according to the manufacturing process of a fibrous preform as described previously,

[0031] - the densification of the fibrous preform by a matrix so as to obtain the part made of composite material.

[0032] According to a particular embodiment of the invention, the part obtained is a part made of ceramic matrix composite material (CMC).

[0033] According to a particular embodiment of the invention, the part obtained is a part made of organic matrix composite material (OMC).

[0034] According to a particular embodiment of the invention, the process further comprises, prior to the densification of the fibrous preform, the consolidation of the fibrous preform by chemical infiltration in the gas phase.

[0035] According to a particular embodiment of the invention, densification is achieved by introducing silicon carbide particles into the porosities of the fibrous preform and then infiltrating the fibrous preform with a molten silicon-based composition.

[0036] A densification process of the "Slurry Cast" type followed by "Melt Infiltration" is thus used to obtain a part made of composite material with a very low porosity rate. Brief description of the drawings

[0037] [Fig-1] Fig. 1 is a flowchart illustrating two variants of a process of manufacturing a fibrous preform.

[0038] [Fig.2] Fig.2 is a schematic perspective view of a type Jacquard in neutral position allowing the weaving of a fibrous texture.

[0039] [Fig.3] Fig.3 is a schematic perspective view of the loom of the [Fig.l] with a crowd creation allowing the weaving of a fibrous texture.

[0040] [Fig.4] [Fig.4] is a schematic perspective view of the fibrous texture exiting from the loom of figures 2 and 3.

[0041] [Fig. 5] Fig. 5 is a schematic perspective view of the fibrous texture of the [Fig.4] stiffened by a resin.

[0042] [Fig.6] Fig.6 is a schematic perspective view of a fibrous blank cut from the stiffened fibrous texture of [Fig.5].

[0043] [Fig.7] Fig.7 is a schematic cross-sectional view of the fibrous blank of the [Fig.6] shaping in a mold so as to obtain a rigidified fibrous preform.

[0044] [Fig-8] The [Fig.8] is a schematic cross-sectional view of the fibrous preform of the [Fig.7] after removal of the resin.

[0045] [Fig.9] The [Fig.9] is a flowchart illustrating an example of a process for manufacturing a part in composite material from the fibrous preform of the [Fig.8]. Description of the implementation methods

[0046] Fig. 1 illustrates a manufacturing process for a fibrous preform according to the invention, with two variants shown.

[0047] The process for manufacturing the fibrous preform includes a first step 1000 of weaving a fibrous texture 200. The fibrous texture 200 is achieved by weaving between a plurality of warp yarns and a plurality of weft yarns.

[0048] Figures 2 and 3 illustrate a loom 100 for producing the fibrous texture 200 used to form the fibrous preform. The loom 100 produces the fibrous texture 200 by weaving a plurality of warp yarns 210 with a plurality of weft yarns 220. The fibrous texture 200 extends lengthwise along a horizontal direction DH and thicknesswise along a vertical direction Dv on the loom 100.

[0049] The loom is equipped with a Jacquard mechanism 110 supported by a superstructure not shown in Figures 2 and 3. The loom 100 also includes a harness 120 comprising control or heddle wires 121, each control wire 121 being connected at one end to a control element 111 of the Jacquard mechanism 110. In the example illustrated in Figures 2 and 3, each control wire 121 is connected at one end to a control hook 111 of the Jacquard mechanism 110 and at the other end to a return spring 112 fixed to the frame 113 of the loom 100. The control wires 121 extend in the vertical direction Dv. The harness 120 may also include a heddle board 122.

[0050] Each control wire 121 includes an eyelet 121a through which a warp wire 210 passes. Each warp wire 210 of the loom 100 passes through an eyelet 121a of the harness 120. The warp wires 210 are arranged in a plurality of horizontal layers and vertical columns and are manipulated by the loom 100 to allow the insertion of weft wires 220 according to the weaving pattern(s) programmed in the loom 100. The weft wires 220 are inserted between the warp wires 210 by column extending along the vertical direction Dv. To allow the introduction of each column of weft threads 220 during the weaving of texture 200, a warp thread calling system 210 (not shown in Figures 2 and 3) is associated with the loom 100. This system, located downstream of the loom 100, has the following role: to hold all the warp threads 210 together in a clamping device and to allow the advancement of the warp threads 210 a determined distance along the horizontal direction DH after the insertion of each weft column 220.

[0051] The terms "upstream" and "downstream" are defined here according to the direction of advance of the warp threads 210 in the loom 100, that is to say according to the direction of weaving, along the horizontal direction DH.

[0052] The control wires 121 and their associated eyelet 121a are able to move along the vertical direction Dv. In [Fig.2], all the control wires 121 are in a neutral position in which no tension is exerted by the Jacquard mechanism 110. In this configuration, no swarm is created and all the warp wires 210 extend parallel to the horizontal direction DH.

[0053] During the creation of a swarm, as illustrated in [Fig.3], part of the control wires 121 are subjected to tensile forces exerted by the control hooks 111. In this configuration, the control wires allow warp wires to be raised or lowered, so as to separate an upper layer of warp wires from a lower layer of warp wires by an opening, called a swarm.

[0054] The loom 100 also includes a spear 130, located downstream of the control wires 121. The spear 130 is composed of a rod 131, the first end of which is connected to an actuation system (not shown in Figures 2 and 3) allowing the rod 131 to be animated with a back-and-forth movement. The other end of the rod 131 is equipped with a gripper 132 which, after passing through the swarm during the rod 131's forward journey, can grasp a weft yarn 220 stored on a reel 140 and unwind it into the swarm during the rod 131's return journey. The weft yarn 220 thus placed inside the swarm is then cut in the vicinity of the reel 140 by a cutting tool 150 and released at its other end by the gripper 132. A comb 160 located upstream of the spear 130 and downstream of the harness 120 in its resting position is then folded down to compact the weft yarn(s) 220 introduced into the swarm.The lance 130 is then ready to pick up a new weft yarn 220 from the bobbin 140 and place it either in the same sheaf or in a different sheaf depending on the defined weave. The fibrous texture 200 is thus progressively formed, exhibiting a weave between the warp yarns 210 and the weft yarns 220.

[0055] Preferably, the loom 100 further comprises a guiding device 170 for the fibrous texture 200 located downstream of the control wires 121 and the spear 130. Such a guiding device 170 is described in particular in document FR 3 074 195 AL. In the example described here, the guiding device 170 comprises a lower jaw 171 and an upper jaw 172, each connected to an actuation means (not shown in Figures 2 and 3) which is capable, on the one hand to maintain the fibrous texture 200 and on the other hand to move the jaws 171 and 172 along the vertical direction Dv. It is thus easier to create crowds at the level of the lower or upper layers of warp yarns 210, even with a large number of layers of warp yarns 210 superimposed in the vertical direction Dv.

[0056] The fibrous texture 200 can be produced in a well-known manner by three-dimensional weaving. "Three-dimensional weaving" here refers to a weaving method in which at least some of the warp yarns interlock with weft yarns over several weft layers. A fibrous texture produced by three-dimensional weaving is considered to include another type of weave on its surface, for example, two-dimensional weaving, in order to improve its surface finish. The fibrous texture may, for example, have a three-dimensional weave structure of the interlock or multisatin type. Various three-dimensional weaving methods that can be used to form the fibrous texture are described in document WO 2006 / 136755.

[0057] An example of such a fibrous texture 200 is illustrated in [Fig. 4]. The fibrous texture 200 comprises at least one woven portion 204. The woven portion 204 of the fibrous texture 200 is intended to be separated from the rest of the fibrous texture 200 to obtain a fiber blank. The fibrous texture may comprise several woven portions, each intended to form a fiber blank. The warp and weft yarns may be interchanged in [Fig. 4].

[0058] In the example illustrated in the figures, the fibrous texture 200 is produced without unbinding. It is of course still within the scope of the invention if the woven portion 204 has one or more unbindings, in order to obtain a fibrous blank comprising one or more unbindings.

[0059] As illustrated in [Fig. 1], a second step 2000 is then carried out involving the impregnation and stiffening of the fibrous texture 200 with a thermoplastic resin. This second step 2000 thus results in a stiffened fibrous texture 300, as illustrated in [Fig. 5].

[0060] The fibrous texture 200 is impregnated with the thermoplastic resin. The thermoplastic resin is then hardened inside the fibrous texture 200 to obtain the stiffened fibrous texture 300. The woven portion 204 of the fibrous texture 200 is also impregnated with the resin and hardened to form a stiffened woven portion. The stiffened woven portion corresponds at least in part to the stiffened fibrous blank 400 to be obtained.

[0061] The thermoplastic resin is preferably transparent or translucent after hardening. Thus, the presence of the hardened thermoplastic resin in the rigidified fibrous texture does not prevent the identification of any tracer or marker threads present on the surface of the weave. In particular, the resin used may be a aqueous solution comprising polyvinyl alcohol (PVA) or poly(2-ethyl-2-oxazoline), which are easily removed with water.

[0062] According to [Fig. 1], a third step 3000 is then carried out, cutting the stiffened fibrous texture 300 to obtain at least one fibrous blank 400. [Fig. 6] illustrates an example of a resin-stiffened fibrous blank 400. Cutting the fibrous blank 400 from within the stiffened fibrous texture 300 can be carried out in a well-known manner by laser cutting. Cutting the fibrous blank 400 from within the stiffened fibrous texture 300 can also be carried out in a well-known manner by waterjet cutting.

[0063] Because the rigid fibrous texture 300 is rigid, its cutting is simplified and more precise. Indeed, the fibrous texture is not flexible and is therefore not slightly deformed during cutting. The risk of non-conformities is thus reduced. If the woven portion of the rigid fibrous texture 300 includes tracer or guide threads and the hardened resin is transparent or translucent, the location and correct positioning of the tracer / guide threads are facilitated in preparation for cutting.

[0064] In the example illustrated in [Fig. 6], for the sake of simplicity, the fiber blank 400 has a simple rectangular parallelepiped shape. Of course, the shape and dimensions of the fiber blank 400 must be adapted according to the final part to be produced.

[0065] Once the fiber blank 400 is obtained, two variants are proposed according to [Fig. 1]. According to a first preferred variant, a fourth step 4000 is then carried out to shape the fiber blank 400 to obtain a stiffened fiber preform 500, followed by a fifth step 5000 to remove the thermoplastic resin in order to obtain the final fiber preform 600 not stiffened by the resin. According to a second variant, the fifth step 5000 to remove the thermoplastic resin is carried out first to obtain a non-stiffened fiber blank 400bis, followed by the fourth step 4000 to shape the fiber blank 400bis to obtain the final fiber preform 600 not stiffened by the resin.

[0066] Figure 7 illustrates the shaping of the fiber blank 400 into a stiffened fiber preform 500, according to the first preferred embodiment. In the example shown in Figure 7, the stiffened fiber preform 500 is obtained from a single fiber blank 400. The fiber blank may include one or more unbonds. The fiber blank may have no unbonds. The stiffened fiber preform may be obtained by winding or bending the fiber blank. It is, of course, within the scope of the invention if the fiber preform is obtained by assembling several fibrous blanks. In particular, the stiffened fibrous preform can be obtained by stacking several fibrous blanks.

[0067] The shaping of the stiffened fiber blank 400 may include heating the thermoplastic resin present in the stiffened fiber blank 400 to soften said resin so as to obtain a deformable fiber blank. The deformable fiber blank can thus be shaped more easily. When the deformable fiber blank(s) are shaped to the desired form, the thermoplastic resin present in the deformable fiber blank(s) is cooled so as to obtain the stiffened fiber preform 500.

[0068] The fibrous blank 400 is shaped in a mold 700.

[0069] According to a first embodiment of the first variant illustrated in Figures 7 and 8, the shaping of the fibrous blank 400 is carried out in a mold that will be used for the consolidation or densification of the resulting fibrous preform. The fifth step 5000 of removing the thermoplastic resin is carried out while the stiffened fibrous preform 500 is in the mold that will be used for the consolidation or densification of the resulting fibrous preform. Thus, in this first embodiment of the first variant, the mold used for the consolidation or densification of the fibrous preform is the mold used during the shaping step of the stiffened fibrous blank 400. The mold used during the removal of the thermoplastic resin is the mold used during the shaping step of the stiffened fibrous blank 400.

[0070] In the example illustrated in [Fig. 7], the shaping of the fibrous blank 400 is carried out in a mold 700, which is a conformer. The conformer 700 comprises a first plate 710 and a second plate 720. The first and second plates 710 and 720 are respectively perforated by orifices 711 and 721 for the passage of reactive gases. Other shapes or types of conformer are, of course, possible. This conformer 700 can subsequently be used to perform a gaseous interphase deposition or gaseous consolidation of the final, unrigidified fibrous preform 600, for example, a chemical vapor infiltration (CVI).

[0071] The shaping of the fibrous blank can also be carried out in an injection mold, for example in a mold for injection called "RTM" for "Resin Transfer Molding" in English.

[0072] According to a second embodiment of the first variant (not illustrated), the fourth step 4000 of shaping the fibrous blank 400 into a stiffened fibrous preform 500 can be carried out in a simple shaping mold. The stiffened fibrous preform 500 is then removed from the shaping mold to be placed in a second mold, different from the shaping mold. This second mold This could be the mold used to consolidate or densify the fibrous preform, for example, a conformer or an injection mold as described previously. The fifth step, 5000, of removing the thermoplastic resin is carried out while the stiffened fibrous preform, 500, is placed in the second mold. Thus, in this second embodiment of the first variant, the mold used for consolidating or densifying the fibrous preform is different from the mold used in the shaping step of the stiffened fibrous blank, 400.

[0073] The stiffened fiber blank 400 is easier to handle for shaping in the first variant, thus reducing the risk of non-conformities. If the fiber blank 400 includes tracer wires or guide wires and the cured resin is transparent or translucent, the location and correct positioning of the tracer / guide wires in the mold are facilitated.

[0074] Figure 8 illustrates the final unrigidified fibrous preform 600 obtained after removal of the thermoplastic resin. Preferably, the final unrigidified fibrous preform 600 is retained in the mold used for the fifth step 5000 of thermoplastic resin removal until it consolidates or densifies.

[0075] Thermoplastic resin can, for example, be removed by heat treatment, ultrasonic treatment, or the application of a solution, or by a combination of these methods. The chosen removal method must be suitable for the type of thermoplastic resin used. The chosen removal method can also be adapted to the accessibility of the fiber blank or fiber preform in the mold. In the case of removal by heat treatment, the thermoplastic resin can be exposed to a temperature suitable for said resin, for example, 450°C. In this case, the temperature increase can be achieved by heating the mold. In the case of removal by ultrasound, an ultrasonic bath can be used. In the case of removal by the application of a solution, the chosen solution must be suitable for said resin and a suitable temperature must be chosen.In particular, if the resin used is polyvinyl alcohol (PVA), it can be removed with water at a temperature above 90°C. Removal by application of a solution can be carried out using an ultrasonic bath. This paragraph applies to both the first and second variants described previously and illustrated in [Fig. 1].

[0076] This yields the final, unstiffened fibrous preform 600, intended to form the fibrous reinforcement of a composite material part. The final, unstiffened fibrous preform 600 is resin-free. Preferably, the final, unstiffened fibrous preform 600 consists solely of fibers.

[0077] The final, unstiffened fibrous preform 600 is intended to be densified by at least one matrix to obtain the desired composite material part. Thus, the final fibrous preform 600 manufactured according to the process as described above can be intended to form all or part of the fibrous reinforcement of a blade, a distributor, a turbine ring, a turbomachine housing, or an angle bracket.

[0078] Figure 9 illustrates an example of a process for manufacturing a part made of composite material from the final fibrous preform 600 described above. Other processes are of course conceivable for producing said part made of composite material from the final fibrous preform 600.

[0079] According to an optional sixth step 6000, an interphase is formed on the fibers of the final fibrous preform 600 in a well-known manner. The interphase can be depositioned using a gaseous process. The interphase can be single-layered or multi-layered. The interphase can comprise one or more layers of pyrolytic carbon, boron nitride, or boron-doped carbon, the boron-doped carbon having an atomic boron content of between 5% and 20%, the remainder being carbon. The sixth step 6000 is preferably carried out while the final fibrous preform 600 is retained in the mold used for the fifth step 5000 of thermoplastic resin removal.

[0080] According to an optional seventh step 7000, the final fibrous preform 600 is consolidated. This consolidation can be carried out using a well-known method of chemical infiltration in the gas phase, known as "CVI". The seventh step 7000 allows for the formation of a consolidation phase within the pores of the final fibrous preform 600.

[0081] The seventh step 7000 is preferably carried out while the final fibrous preform 600 is kept in the mold used for the fifth step 5000 of thermoplastic resin removal.

[0082] The consolidation phase may consist solely of silicon carbide. Alternatively, the consolidation phase may include, in addition to silicon carbide, a self-healing material. A self-healing material containing boron may be chosen, for example, a Si-BC ternary system or boron carbide capable of forming, in the presence of oxygen, a borosilicate glass with self-healing properties. The thickness of the consolidation phase deposit may be greater than or equal to 500 nm, for example, between 1 pm and 30 pm. The outermost layer of the consolidation phase, i.e., the layer furthest from the fibers, is advantageously made of silicon carbide in order to constitute a reaction barrier between the underlying fibers and the subsequently introduced molten silicon composition.

[0083] The thickness of the consolidation phase is sufficient to consolidate the fibrous preform, that is, to bind the fibers of the preform together sufficiently so that the preform can be manipulated while retaining its shape without the assistance of holding tools. After this consolidation, the preform remains porous, the initial porosity being, for example, only partially filled by the interphase and the consolidation phase.

[0084] According to an eighth step 8000, a slurry comprising a powder of silicon carbide particles is injected in a well-known manner into the fibrous preform according to the process known as "Slurry Cast" or "Slurry Transfer Molding" in English.

[0085] According to a ninth step 9000 carried out after the eighth step 8000, a molten composition consisting mainly of molten silicon by mass is infiltrated into the remaining pores of the fibrous preform. This infiltration is known in English as "melt infiltration." This composition may consist of molten silicon alone or a molten silicon alloy which also contains one or more other elements such as titanium, molybdenum, boron, iron, or niobium. The silicon content by mass in the molten composition may be greater than or equal to 90%.

[0086] Such a process makes it possible to obtain a part made of ceramic matrix composite material with a very low porosity. Of course, this does not depart from the scope of the invention if the part produced is not ceramic matrix. Indeed, the present invention can also be used to manufacture parts made of organic or metallic matrix composite material.

[0087] The composite material part obtained by the process as described above can be a blade, a distributor, a turbine ring, a turbomachine casing or an angle iron, or at least a part of one of these elements.

Claims

Demands

1. A method for manufacturing a fibrous preform (600) intended to form the fibrous reinforcement of a part made of composite material, comprising: - (1000) the creation of at least one fibrous texture (200) by weaving between a plurality of warp yarns and a plurality of weft yarns, - (3000) cutting said at least one fibrous texture (200) so as to obtain one or more fibrous blanks (400), - (4000) shaping the fibrous blank(s) (400) so as to obtain a fibrous preform (600), the method being characterized in that said at least one fibrous texture (200) is impregnated with a thermoplastic resin and in that said resin is hardened before cutting said at least one fibrous texture (200) so that the cutting is carried out on a stiffened fibrous texture (300),the thermoplastic resin being removed after cutting the rigidified fibrous texture (300) or after shaping the fibrous blank(s) (400).

2. A manufacturing method according to claim 1, wherein the thermoplastic resin is removed after shaping the fibrous blank(s) (400).

3. A manufacturing method according to claim 2, wherein, during the shaping step (4000), at least the portion or portions of the fibrous blank(s) (400) to be shaped are heated to a thermoplastic resin softening temperature.

4. A manufacturing method according to claim 3, wherein during the shaping step (4000) the fibrous blank(s) (400) are heated locally so that at least a portion of the thermoplastic resin remains hardened.

5. A manufacturing method according to any one of claims 1 to 4, wherein the shaping of the fibrous blank(s) (400) is carried out in a mold (700).

6. A manufacturing method according to any one of claims 2 to 4, wherein the shaping step (4000) of the fibrous blank(s) (400) is carried out in a first shaping mold and wherein the thermoplastic resin removal step (5000) is carried out while the fibrous preform (500) is placed in a second mold different from the first mold.

7. A manufacturing method according to any one of claims 2 to 4, wherein the shaping step (4000) of the fibrous blank(s) (400) and the thermoplastic resin removal step (5000) are carried out in the same mold (700) configured for the consolidation or densification of the fibrous preform (600).

8. A manufacturing method according to any one of claims 1 to 7, wherein the cured thermoplastic resin is transparent or translucent.

9. A manufacturing process according to any one of claims 1 to 8, wherein the thermoplastic resin comprises polyvinyl alcohol (PVA) or poly(2-ethyl-2-oxazoline).

10. A method for manufacturing a part made of composite material comprising: - manufacturing a fibrous preform (600) according to any one of claims 1 to 9, - densifying the fibrous preform (600) by a matrix so as to obtain the part made of composite material.

11. A manufacturing method according to claim 10, wherein the part obtained is a part made of ceramic matrix composite material or organic matrix composite material.

12. A manufacturing process according to claim 10 or 11, the process further comprising, prior to densification of the fibrous preform, consolidation of the fibrous preform by chemical infiltration in the gas phase.

13. A manufacturing method according to any one of claims 10 to 12, wherein densification is achieved by introducing silicon carbide particles into the porosities of the fibrous preform and then infiltrating the fibrous preform with a molten silicon-based composition.

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