Conforming tooling with variable opening ratio for gas flow

Abstract

Conforming tool with variable opening ratio for gas flow. The invention relates to a tool (1) for conforming a fibrous texture (2) for gas-phase consolidation, comprising: - a first conforming zone (11) configured to bear against the texture and locally conform it to a first thickness, the first conforming zone having a plurality of first gas supply orifices (13) defining a first opening ratio for gas flow, and - a second conforming zone (12) configured to bear against the texture and locally conform it to a second thickness less than the first thickness, the second conforming zone having a plurality of second gas supply orifices (14) defining a second gas flow ratio less than the first opening ratio. Figure for the abstract: Fig. 1.

Description

Title of the invention: Conforming tool with variable opening ratio for gas passage Technical field

[0001] The present invention relates to a tooling for shaping a fibrous texture for gas-assisted consolidation, adapted to textures exhibiting variations in thickness, and associated consolidation and manufacturing processes for a composite part. A particular application of the invention is the manufacture of parts made of ceramic matrix composite material ("Ceramic Matrix Composite"; "CMC"), for example, silicon carbide matrix composites. Prior art

[0002] Composite material parts are increasingly used in aeronautical turbomachinery to reduce the weight of structures compared to metallic materials, while still guaranteeing the desired mechanical properties. In particular, hot section parts are advantageously made of thermostructural composite material that has the ability to retain its mechanical properties at high temperatures. The manufacture of such parts involves obtaining a reinforcing texture, notably by three-dimensional weaving, which is then shaped in a forming tool to obtain a preform of the part to be produced.The forming tooling is usually made of graphite and is multi-perforated to allow the infiltration of a gaseous phase containing one or more precursors. This process is called consolidation, and in this step, material is deposited into a porosity of the texture formed in the conformator using the gaseous precursor(s). The thickness of the deposited material is sufficient to bind the fibers of the preform together, allowing it to be manipulated while maintaining its shape without the need for support tooling. The part manufacturing process can then be completed by densifying the residual porosity of the consolidated preform, for example, by molten infiltration.Conformer consolidation techniques can lead to material deposition gradients in the texture thickness when the texture has a variable thickness, as in the case of a texture forming a turbine blade reinforcement which has a root portion that is significantly thicker than the aerodynamic blade profile. Statement of the invention

[0003] The invention relates to a tooling for shaping a fibrous texture for gaseous consolidation, comprising: - a first conformation zone configured to rest on the texture and conforming it locally to a first thickness, the first conforming zone having a plurality of first gas supply orifices defining a first opening rate for the passage of gas, and - a second conformation zone configured to support the texture and conform it locally to a second thickness less than the first thickness, the second conformation zone having a plurality of second gas supply orifices defining a second opening rate for the passage of gas less than the first opening rate.

[0004] The shaping tooling according to the invention is remarkable in that it features a variation in the gas flow rate, which is intended to create a consolidation phase within the texture's porosity, adapted to the texture's thickness variation. The gas flow rate is thus greater in the area where the texture is thicker, resulting in more homogeneous consolidation.

[0005] In one embodiment, the second opening ratio for gas passage is less than or equal to half of the first opening ratio for gas passage.

[0006] Such a feature is particularly suited to the consolidation of a texture having a large variation in thickness such as a texture intended to form the reinforcement of a blade made of composite material.

[0007] In one embodiment, the first thickness is greater than or equal to 10 mm and the first opening rate for gas passage is greater than or equal to 18%, and the second thickness is less than or equal to 10 mm and the second opening rate for gas passage is less than or equal to 10%.

[0008] In particular, the first open rate can be between 18% and 50%. Alternatively, or in combination, the second open rate can be between 6% and 10%.

[0009] In one embodiment, the first and second conformation zones comprise an oxide ceramic material.

[0010] Such a characteristic allows more freedom in the possible variations of the opening ratio compared to the use of graphite tooling and makes it possible to reduce its cost.

[0011] In particular, the oxide ceramic material can be chosen from alumina or zirconia.

[0012] These materials advantageously exhibit high dimensional stability during gaseous consolidation.

[0013] The invention also relates to a method for manufacturing a consolidated fibrous preform, comprising: - a shaping of a fibrous texture in a conforming tool as described above, said fibrous texture being conformed to the first thickness in the first conformation zone and second thickness in the second conformation zone so as to obtain a fibrous preform, and - a gaseous consolidation of the preform held in the forming tooling by supplying the first and second feed orifices with a gaseous phase comprising one or more precursors of a consolidation phase so as to obtain the consolidated fibrous preform.

[0014] In one embodiment, the preform is a turbine blade preform, a blade root preform being formed in the first conformation zone and a blade preform being formed in the second conformation zone.

[0015] In one embodiment, the fibrous preform is consolidated by a silicon carbide phase.

[0016] The invention also relates to a method for manufacturing a part made of composite material, comprising: - the manufacture of a consolidated fibrous preform by implementing a process as described above, and - the densification of the consolidated preform by a matrix phase.

[0017] In one embodiment, densification is achieved by infiltration in the molten state.

[0018] The part may be a turbomachine part, for example, an aeronautical turbomachine part. In particular, the part may be a turbine part, such as a turbine blade, a distributor sector, or a ring sector. Brief description of the drawings

[0019] [Fig-1] Fig. 1 is a schematic and partial perspective view of an example of shaping tooling according to the invention.

[0020] [Fig.2] The [Fig.2] is a cross-sectional view along ILII of the tooling of the [Fig.l].

[0021] [Fig.3] Fig.3 is a very schematic view showing the evolution of the rate opening for the passage of gas for an example of a shaping tool according to the invention. Description of the embodiments

[0022] Fig. 1 represents an example of a shaping tool 1 according to the invention adapted for shaping a fibrous texture 2 intended to form the fibrous reinforcement of a turbine blade for an aeronautical turbomachine, it being understood that the invention is not limited to this application as indicated above.

[0023] Tooling 1 is adapted to the gaseous consolidation technique during which tooling 1, maintaining texture 2 in the desired shape, is present in a chemical vapor infiltration furnace ("Chemical Vapor Infiltration"; "CVI"). A gaseous phase comprising one or more precursors of a phase of The desired consolidation material is introduced into tooling 1 through feed ports 13 and 14, which will be described in more detail later. Consolidation produces a so-called consolidated preform that can be manipulated while retaining its shape without the assistance of the holding tooling. Consolidation is a well-known technique, for example, using a gaseous phase comprising methyltrichlorosilane and hydrogen to form a silicon carbide consolidation phase.

[0024] Texture 2 is initially manufactured by implementing one or more textile operations, for example by three-dimensional weaving, in a manner known per se. Texture 2 can be made of ceramic fibers, for example silicon carbide or carbon. Texture 2 is positioned in tooling 1, which here comprises a first block 101, in the form of an upper block, and a second block 102, in the form of a lower block. Those skilled in the art will recognize that other arrangements are possible depending on the geometry of the part to be obtained. Blocks 101 and 102 rest on texture 2, which is located between them. Blocks 101 and 102 allow texture 2 to be shaped and compacted to a target thickness in the area concerned, so as to guarantee the desired fiber content.Blocks 101 and 102 define a plurality of housings 17 for the insertion of locking elements (not shown) to allow the tooling 1 to be closed and to ensure that the texture 2 is held in place before being placed in the oven. In the illustrated example, each of the blocks 101 includes several lugs 16 arranged around its periphery, each lug 16 defining an insertion housing 17.

[0025] As mentioned above, the tooling 1 is remarkable in that it has an opening ratio for the passage of gas that varies according to the area considered. More specifically, the tooling 1 comprises a first conforming zone 11 bearing against the texture 2, here on the part 21 intended to form the blade root, and allows this part 21 to be conformed to a first thickness el. The first zone 11 comprises a first conforming element 111, belonging to the first block 101, and a second conforming element 112, belonging to the second block 102. The part 21 is taken between the elements 111 and 112 so as to be conformed to the first thickness el. The first zone 11 has a plurality of first gas supply orifices 13 through which the gaseous phase comprising the precursor(s) of the consolidation phase is intended to flow to reach the shaped texture 2 and deposit the consolidation phase in its porosity.The first orifices 13 are present in an area of ​​the tooling 1 bearing on the texture 2 to allow its shaping, in particular its compaction to the first thickness el. In the example considered, the elements 111 and 112 each have the first . The invention remains within the scope of the invention when texture 2 is supplied only by the first block 101 or by the second block 102. The first orifices 13 are located in a delimited area between a first PI and a second P2 transverse plane to a longitudinal X axis of texture 2. Generally, the first thickness el can be greater than or equal to 10 mm, for example, between 10 mm and 20 mm, and the first gas flow rate greater than or equal to 18%, for example, between 18% and 50%. Unless otherwise specified, the gas flow rate of a conformation zone is understood as the total gas flow area of ​​the conformation zone divided by the surface area of ​​that conformation zone. The first orifices 13 may be substantially the same size or different sizes. The first 13 orifices may have roughly the same shape or different shapes.

[0026] The tooling 1 also includes a second shaping zone 12 bearing against the texture 2, here on the portion 22 intended to form the blade of the fan, and allows this portion 22 to be shaped to a second thickness e2. The second zone 12 comprises a first shaping element 121, belonging to the first block 101, and a second shaping element 122, belonging to the second block 102. The portion 22 is taken between the elements 121 and 122 so as to be shaped to the second thickness e2. The second zone 12 has a plurality of second gas supply orifices 14 through which the gaseous phase comprising the precursor(s) of the consolidation phase is intended to flow to reach the shaped texture 2 and deposit the consolidation phase in its porosity.The second orifices 14 are located in an area of ​​the tooling 1, bearing against the texture 2 to allow for its shaping, specifically its compaction to the second thickness e2. In the example considered, elements 121 and 122 each have the second orifices 14, but this does not depart from the scope of the invention if it is otherwise, as indicated above. The second orifices 14 are located in an area delimited between the second P2 and a third P3, which is transverse to the X-axis. Generally, the second thickness can be less than or equal to 10 mm or less than or equal to 3 mm, for example, between 1 mm and 10 mm or between 1 mm and 3 mm, and the second opening ratio for gas passage can be less than or equal to 10%, for example, between 6% and 10%. The second orifices 14 may be roughly the same size or may be different sizes.The second orifices 14 may have essentially the same shape or different shapes. The first 13 and second 14 orifices may or may not have the same size. The first 13 and second 14 orifices may or may not have the same shape.

[0027] Various materials can be used to form the tooling 1 and in particular its conformation zones 11 and 12. Graphite, or a material, can be used for this purpose. A ceramic oxide is used if a wide range of aperture sizes is desired. Generally, the choice of material for tooling 1 also depends on the conditions encountered during consolidation. The orifices 13 and 14 can be formed by machining or by focusing an energy beam. Forming the conformation zones by additive manufacturing can also be considered for creating complex aperture patterns.

[0028] The example just described relates to a tool 1 having two conformation zones 11 and 12, but we do not leave the scope of the invention when it includes more conformation zones and in particular a third conformation zone configured to support the texture and conform it locally to a third thickness different from the first and second thicknesses, the third conformation zone having a plurality of third gas supply orifices defining a third opening rate different from the first and second opening rates.

[0029] The process can then be continued by densifying the consolidated preform, forming a matrix phase within its residual porosity using techniques known per se. A part made of a ceramic matrix composite material, for example a silicon carbide matrix, can thus be obtained. As an example, densification can be achieved by molten silicon infiltration (the "melt-infiltration" process). In this case, a powder is introduced into the residual porosity of the consolidated preform. This powder can be carbon powder, ceramic powder, silicon carbide powder, or a mixture of such powders. A molten silicon-based metallic composition is then infiltrated to form a SiC or SiC-Si matrix.Those skilled in the art will recognize that other techniques can be used for densification, such as chemical vapor infiltration or polymer infiltration and pyrolysis (“Polymer Infiltration and Pyrolysis”; “PIP”).

[0030] The expression "between ... and ..." should be understood as including the bounds.

Claims

Claims

1. Tool (1) for shaping a fibrous texture (2) for gas consolidation, comprising: - a first shaping zone (11) configured to bear on the texture and locally shape it to a first thickness (e1), the first shaping zone having a plurality of first gas supply orifices (13) defining a first opening rate for the passage of gas, and - a second shaping zone (12) configured to bear on the texture and locally shape it to a second thickness (e2) less than the first thickness, the second shaping zone having a plurality of second gas supply orifices (14) defining a second opening rate for the passage of gas less than the first opening rate, in which the first thickness is greater than or equal to 10 mm and the first opening rate for the passage of gas is between 18% and 50%,and wherein the second thickness is less than or equal to 10 mm and the second opening rate for the passage of gas is between 6% and 10%.,

2. Conforming tool (1) according to claim 1, in which the second opening rate for the passage of gas is less than or equal to half of the first opening rate for the passage of gas.

3. A shaping tool (1) according to claim 1 or 2, wherein the first (11) and second (12) shaping zones comprise an oxide ceramic material.

4. Tooling (1) according to claim 3, in which the oxide ceramic material is chosen from alumina or zirconia.

5. A method of manufacturing a consolidated fibrous preform, comprising: - shaping a fibrous texture (2) in a shaping tool (1) according to any one of claims 1 to 4, said fibrous texture being shaped to the first thickness (e1) in the first shaping zone (11) and to the second thickness (e2) in the second shaping zone (12) so as to obtain a fibrous preform, and - gaseous consolidation of the preform held in the shaping tool by supplying the first (13) and

6.

7.

8.

9. second (14) feed orifices with a gas phase comprising one or more precursors of a consolidation phase so as to obtain the consolidated fibrous preform. The method of claim 5, wherein the preform is a turbine blade preform, a blade root preform being formed in the first shaping zone (11) and a blade preform being formed in the second shaping zone (12). A method according to claim 5 or 6, wherein the fibrous preform is consolidated by a silicon carbide phase. Method for manufacturing a part made of composite material, comprising: - the manufacture of a consolidated fiber preform by implementing a method according to any one of 5 to 7, and - densification of the consolidated preform by a matrix phase. Method according to claim 8, in which the densification is carried out by infiltration in the melt state.

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