FR3162015A1 - Tooling for manufacturing an aeronautical part and a method for manufacturing the aeronautical part using this tooling - Google Patents

Abstract

The invention relates to a tool (6) for manufacturing an aeronautical part, the tool comprising two rigid shells (62, 64) assembled to define a cavity (60) for receiving a fibrous preform (520), wherein at least one of the shells comprises a through opening (800), and an elastically deformable membrane (82) extending at the level of this opening and defining a first injection compartment (880) opening into the cavity, and a second compaction compartment (882) separated from the cavity by the membrane. The tool further comprises at least one first port (804) connected to the first compartment and configured to be connected to a resin source, and at least one second port (884, 886) connected to the second compartment and configured to be connected to a compaction fluid source. Figure 6

Description

Tooling for manufacturing an aeronautical part and a method for manufacturing the aeronautical part using this tooling Technical field of the invention

The present invention relates to the field of manufacturing aeronautical parts.

More specifically, the present invention relates to tooling for manufacturing an aeronautical part, particularly for an aircraft turbomachine. The present invention also relates to a method for manufacturing such an aeronautical part using such tooling, as well as an aeronautical part obtained by such a manufacturing method.

Technical background

Some aeronautical components can be made of composite materials (such as aircraft structures, turbomachine parts, etc.). For example, a housing surrounding a turbomachine fan can be made of composite material. These aeronautical components are generally composed of a fibrous preform and a polymer resin matrix. The fibrous preform gives the composite material its mechanical strength, and the polymer matrix binds the fibers of the fibrous preform together so that the final composite material is rigid, ductile, and not brittle.

In the prior art, there are several manufacturing processes for such parts, notably from so-called dry preforms (that is, without prior impregnation of the fibrous preform with resin).

For example, it is known to produce such parts from composite materials using a resin transfer molding (RTM) process. The RTM process uses tooling typically composed of rigid shells (or, in other words, a rigid mold and counter- mold ) which, once assembled, close a cavity. A fibrous preform is placed in this cavity, and then a liquid resin (which becomes viscous after one or more heating cycles) is injected to impregnate the fibrous preform. The resin is then cured in an autoclave, once the shell halves are closed and resin injectors are connected.

Figures 1 and 2 illustrate an example of tooling 6 for the RTM process, which comprises at least two rigid shells 62, 64 (or, in other words, mold and counter-mold) assembled to define a cavity 60. Specifically, the tooling includes an inner shell 62 with two internal annular half-shells, and an outer shell 64 with several angular sectors mounted around the internal annular half-shells. Sealing shells 66, 68 are arranged on each end of the inner shell 62 and the outer shell 64. A fibrous preform 520, intended to form a part 5, is placed in the cavity 60.

It is also known to produce composite parts using a process similar to " Polyflex ." In this Polyflex process, the fiber preform is placed on a tooling with a surface having the desired profile for the final part. The fiber preform is then covered with a deformable, impermeable membrane, and a resin is injected under the membrane to impregnate the fiber preform. Above the membrane, another fluid is injected into a second cavity formed by an outer shell and the membrane. This second fluid exerts isostatic pressure on the membrane, deforming it and pressing it against the fiber preform below. The pressure exerted on the membrane by the second fluid forces the resin to impregnate the fibers of the fiber preform and applies pressure to the fiber/resin assembly, which is maintained during the resin polymerization phase. This ensures a good fiber volume ratio (FVR), the ratio of the fiber preform to the cavity volume, and therefore good mechanical properties.

There are also other methods for manufacturing parts from composite materials, such as:
- A VARTM process (English acronym for " Vacuum Assisted Resin Transfer Molding ") is similar to the RTM process during which a vacuum is created inside the cavity in which the fibrous preform is installed in order to facilitate and accelerate the injection of the resin,
- a CRTM process (English acronym for " Compression Resin transfer Molding ") which is an injection-compression process similar to the RTM process during which the shells are spaced apart (i.e. the mold or the inner shell is not closed), and the injection is then carried out and accelerated by opening the mold, then the impregnation of the fibrous preform as well as its final shaping are carried out by moving the moving part of the rigid mold by compression;
- a VARI process (acronym for " Vacuum Assisted Resin Infusion ") or an LRI process (acronym for " Liquid Resin Infusion ") during which the fibrous preform is positioned on an internal shell (or mold) and then covered with a permeable peel ply, felt or drainage material, then with an elastic and impermeable membrane (i.e., vacuum bag). Once the assembly is sealed, a vacuum is drawn under the bag and the liquid resin then impregnates the fibrous preform, filling the space left by the vacuum; or
- a "vacuum bag molding" process which is applicable to pre-impregnated fibrous preforms, or partially coated with resin, and in this process, the final part is obtained by simply baking the fibrous preform; indeed, the polymer matrix is obtained from the resin already present within the fibrous preform (no resin is added during this manufacturing process).

However, these prior art processes only allow the resin to impregnate the fibrous preform, and they do not allow for the creation of composite parts with an area or section enriched in polymer matrix (or, in other words, in resin before its polymerization/curing). This polymer matrix-enriched area can also be referred to as an RRA, which is an acronym for " Resin Rich Area ." Indeed, it can be advantageous to integrate one or more sections composed primarily of polymer matrix (and therefore with a fiber density of zero or less than that of the fibrous preform) to add one or more additional functions to this part.

The reasons identified by the inventors why prior art processes do not allow the creation of RRA parts, particularly in a controlled manner, for example in terms of TVM (acronym for Volumetric Matrix Ratio) in this RRA part, spatial positioning of this RRA part and absence of impact on the TVF and TVM ratios of other parts of the part, are the rigidity of the shells used as well as the bulking of the fibers of the fibrous preform.

Indeed, the use of rigid shells fixes the volume containing the fibrous texture and within which the resin can evolve. To obtain a high TVM (Total Fiber Resistance) for the RRA (Resin-Resin-Area) portion, it would be necessary to leave fiber-free spaces within this volume. However, the fibers will tend to occupy the maximum available space, thus causing fiber bulging. This will affect the desired TVM in the RRA portion and will also affect the final TVF (Total Fiber Resistance) and TVM (Total Fiber Resistance) values in areas of the part near the RRA portion. Consequently, the mechanical properties of the part in these areas will no longer meet expectations.

For example, the FIG. 3 schematically illustrates an empty space E without fibers on a fibrous preform 520 before a resin injection step. After a resin injection step on the FIG. 3 , we observe that this space E is filled with F _D fibers from the fibrous preform 520 by expansion, and the areas close to this space E have F _D fibers dispersed with respect to a desired arrangement of F _I fibers in the final part.

The use of flexible/deformable membrane or vacuum tarpaulin, due to their very high flexibility (compared to rigid shells), does not allow for precise control of the location of RRA parts.

In this context, it is interesting to propose a solution that addresses at least one of the aforementioned drawbacks, in particular by optimizing the production of an aeronautical part and the tooling for manufacturing this part to facilitate the robust and controlled integration of at least one part composed of a polymer matrix.

The present invention offers a simple, effective and economical solution to the aforementioned drawbacks of the prior art.

To this end, the invention proposes a tooling for manufacturing an aeronautical part, in particular for an aircraft turbomachine,
the tooling comprising at least two rigid shells which are assembled to define a cavity between them, this cavity being intended to receive a fibrous preform.

According to the invention, at least one of the shells comprises a through opening, and an elastically deformable membrane which extends at the level of this opening and which defines a first compartment called injection, which opens into the cavity, and a second compartment called compaction which is separated from the cavity by the membrane.

According to the invention, the tooling further comprises at least one first port which is connected to the first compartment and which is configured to be connected to a resin source for the purpose of injecting resin into said first compartment, and at least one second port which is connected to the second compartment and which is configured to be connected to a compaction fluid source for the purpose of supplying the second compartment with compaction fluid.

Thus, this solution makes it possible to achieve the aforementioned objective. Indeed, the tooling according to the invention facilitates the production of an aeronautical part, particularly for the integration of at least one portion composed of a polymer matrix (or, in other words, a resin-enriched portion) onto a fibrous preform. To this end, the tooling comprises, on the one hand, at least two rigid shells defining a cavity to form the fibrous preform, and on the other hand, an elastically deformable membrane defining two distinct compartments to form the portion composed of the polymer matrix. The tooling thus makes it possible to judiciously combine RTM and Polyflex techniques, and the phase-change properties of the resin that will form the polymer matrix. The tooling therefore allows for precise control of the dimensions (shape, size, etc.) and position of this portion composed of the polymer matrix on the fibrous preform. Therefore, the tooling makes it possible to form the desired aeronautical part with the correct proportions of TVF fiber and TVM resin volume percentages, and the bond between the fibrous preform and the part composed of polymer matrix is robust.

By optimizing the manufacturing of aeronautical parts from composite materials, the tooling according to the invention makes it possible to reduce the environmental impact of these parts during operation, particularly in an aircraft turbomachine. Indeed, the composite material reduces the mass of the part, thereby reducing fuel consumption, which in turn leads to a reduction in polluting and/or harmful emissions (such as CO, CO2, NOx, etc.).

The tooling according to the invention may comprise one or more of the following features, considered independently of each other or in combination with each other:

- a flange covers said through opening and defines said second compartment with said membrane;

- the flask includes said at least one second port;

- the number of secondary ports is at least two;

- said at least one first port is formed directly in at least one of the hulls having the through opening;

- the number of first ports is at least two, and the first ports are located on two opposite sides of the through opening;

- the number of shells is greater than two;

- the shells comprise two annular shells, respectively internal and external, and two end annular shells, the cavity defined by these shells being annular;

- the opening and the membrane are located on the outer shell, and in particular on an angular sector of this outer shell.

The present invention also relates to a method for manufacturing an aeronautical part, in particular for an aircraft turbomachine,
the part comprising a monobloc body having two parts joined together, a first of these parts comprising a fibrous preform embedded in a first polymeric matrix, and a second of these parts comprising a second polymeric matrix, the second part having a fiber density of zero or less than that of the first part,
in which this part is made using tooling according to one of the features of the invention.

The process according to the invention also facilitates the production of an aeronautical part incorporating at least one second component composed of a second polymer matrix onto a fibrous preform embedded in a first polymer matrix. Indeed, the process allows the second polymer matrix to be formed directly onto the fibrous preform, notably through the tooling configuration in which the first compartment opens into the cavity containing the fibrous preform. This enables the formation of a robust bond between the fibrous preform embedded in the first polymer matrix and the second component composed of the second polymer matrix, without the use of adhesives or mechanical fasteners such as bolts or rivets.

As mentioned above, the process allows the second part composed of the second polymer matrix to be formed by controlling and modulating the dimensions and position on the first part of the piece.

Furthermore, the integration of this second part composed of the second polymer matrix can give the part one or more new functions or properties, such as a stop function, protection of an external surface of the part, wear indicator, etc.

The method according to the invention may comprise one or more of the following features, considered independently of each other or in combination with each other:

- The process includes the following steps:
(a) placement of the fibrous preform in the tooling cavity,
(c) densification of the fibrous preform by injecting a first resin into the tooling cavity, so as to preform said first polymeric matrix,
(e) injection of a second resin into the first compartment of the tooling, so as to preform said second polymer matrix,
(g) simultaneous polymerization of the first and second resins, so as to form said first and second polymeric matrices;

- the process also includes:
- a first compaction step (b) of the fibrous preform which is carried out between steps (a) and (c), and which includes the injection of the compaction fluid into the second compartment, and/or
- a second compaction step (f) of the densified fibrous preform by the first resin, which is carried out between steps (e) and (g) and which includes the injection of the compaction fluid into the second compartment;

- the process further includes, between steps (c) and (e) a step of emptying (d) the second compartment;

-- the first resin is identical to the second resin;

-- the part can be an annular housing, particularly for aircraft turbomachinery.

The present invention further relates to an aeronautical part for an aircraft turbomachine, the part being obtained by the manufacturing process according to one of the features of the invention, the part comprising the body including the first part with the fibrous preform embedded in the first polymeric matrix, and the second part including the second polymeric matrix and having a fiber density of zero or less than that of the first part, the part being annular (according to a specific but non-limiting example) and said second part being projecting on an external annular surface of the first part.

The second part can be a stop or a protective coating for part or all of the external annular surface of the first part.

The aeronautical component according to the invention has the advantage of incorporating one or more secondary parts composed of a polymer matrix. These secondary parts allow the component to be given one or more new functions or additional properties. For example, these new functions could be at least one of the following:
- protection: the second part can cover part or all of the external annular surface of the first part of the piece, in order to isolate it from the external environment; in this way, the first part corresponding to the structural part of the piece can be protected from external aggressions (such as blows from handling tools);
- mechanics in exceptional conditions: the second part can constitute a functional part of the part, particularly in exceptional conditions; this second part can be, for example, a stop which would serve to block the part (or limit its movements) in the event that it is exceptionally caused to move due to the breakage of an adjacent part;
- mechanics under normal conditions: the second part can also constitute a functional part of the part, particularly in an area of this part not requiring high mechanical resistance; indeed, due to its high TVM rate, this second part will be mechanically weaker than the rest of the part and will be lighter, less expensive and less complex to obtain compared to the first part of the part, especially if this second part does not need to be as mechanically robust as the rest of the part;
- witness: the second part can cover a portion of the part which may be likely to come into contact with an adjacent part or element; in this way, contact will be made with this second part without impacting the structural part of the part (i.e. the first part) and regular inspection of this portion will allow monitoring of the evolution of contact wear.

Brief description of the figures

The invention will be better understood and other details, features and advantages of the invention will become more apparent upon reading the following description, given by way of non-limiting example and with reference to the accompanying drawings in which:

there FIG. 1 is a schematic perspective view of a tooling for manufacturing a part according to the prior art,

there FIG. 2 is a schematic axial cross-sectional view of the tooling of the FIG. 1 ,

there FIG. 3 is a schematic representation of a fibrous preform before resin injection according to the prior art,

there FIG. 3 is a schematic representation of the fibrous preform of the FIG. 3 after resin injection,

there FIG. 4 is a schematic perspective view of an example of tooling for manufacturing an aeronautical part according to the invention,

there FIG. 5 is a schematic, perspective, and enlarged view of part of the tooling of the FIG. 4 ,

there FIG. 6 is a schematic axial cross-sectional view of part of the tooling of the FIG. 5 comprising an elastically deformable membrane,

there FIG. 7 is another schematic axial cross-sectional view of the tooling of the FIG. 6 ,

there FIG. 8 is a schematic, perspective, and enlarged view of an aeronautical part obtained using the tooling of the FIG. 4 ;

there FIG. 9 is a block diagram representing the steps in a manufacturing process for the aeronautical part of the FIG. 8 using the tools of the FIG. 4 ,

there FIG. 10 is a schematic axial cross-sectional view of part of the tooling of the invention in a first compaction stage and a densification stage of the process of the FIG. 9 ,

there FIG. 11 is a schematic axial cross-sectional view of a portion of the tooling of the invention during a step of emptying and injecting a second resin of the process of the FIG. 10 ,

there FIG. 12 is a schematic axial cross-sectional view of part of the tooling in a second compaction stage of the process of the FIG. 10 .

Elements having the same functions in different implementations have the same references in the figures.

Detailed description of the invention

By convention, in the description below, the terms "longitudinal" and "axial" refer to the orientation of structural elements extending along a longitudinal axis (such as in a turbomachine or aircraft component). The terms "radial" or "vertical" refer to the orientation of structural elements extending in a direction perpendicular to the longitudinal axis. The terms "interior" and "exterior," and "internal" and "external," are used to refer to positioning relative to the longitudinal axis. Thus, a structural element extending along the longitudinal axis has an interior face facing the longitudinal axis and an exterior surface opposite its interior surface.

Figures 1, 2, 3a and 3b have been described in the technical background of this application and illustrate an example of tooling for manufacturing an aeronautical part from a fibrous preformer.

Figures 4 to 7 and 10 to 12 illustrate a non-limiting example of a tool 6 according to the invention. This tool 6 makes it possible to manufacture an aeronautical part 5, in particular for an aircraft turbomachine 10.

Tooling 6 can extend along a longitudinal axis A.

The tooling 6 comprises at least two rigid shells 62, 64 which are assembled to define a cavity 60 between them. This cavity 60 is intended to receive a fibrous preform 520. This fibrous preform 520 can be configured to form a first part 52 of the part 5.

The number of shells in tooling 6 can be greater than two.

The two shells 62, 64 may comprise two annular shells, respectively internal 62 and external 64, and two end annular shells 66, 68. The cavity 60 defined by these two shells 62, 64 may be annular. The shells 62, 64, 66, 68 and the cavity 60 may extend around the axis A.

With reference to the FIG. 4 The two end shells 66, 68 can extend on either side of the inner annular shell 62 (also called the inner shell 62), and the outer annular shell 64 (also called the outer shell 64) can extend around and so as to cover the inner shell 62 and the two end shells 66, 68. The two end shells 66, 68 can allow the fibrous preform 520 to be densified to be positioned and locked in the tooling, as well as to reinforce the sealing of the tooling 6.

The annular cavity 60 can be formed in the inner shell 62 or between the inner shell 62 and outer shell 64.

The internal shell 62 can comprise two annular half-shells assembled together.

The internal shell 62 may include a first resin injection port (not shown in the figures), in particular of a first resin R ₁ , allowing for example a densification of the fibrous preform 520.

The outer shell 64 may include a second resin injection port if needed (not shown in the figures), in particular for the first resin R ₁ .

The outer shell 64 can include several angular sectors 640 extending around the axis A. The number of angular sectors 640 can be between two and ten.

The hulls 62, 64, 66, 68 can be made of a metallic material.

One of the distinctive features of the invention is that at least one of the hulls 62, 64 comprises:
- a through opening of 800, and
- an elastically deformable membrane 82 which extends at the level of this opening 800.

Figures 4 to 7 illustrate an example of the tooling 6 according to the invention in which the outer shell 64, and in particular one of the angular sectors 640, comprises the through opening 800 and the membrane 82.

In an alternative not shown, the through opening 800 and the membrane 82 can be located on the inner shell 62.

According to another variant not illustrated, several through openings 800 and several membranes 82 can be located both on the outer shell 64 and the inner shell 62.

The angular sector 640, comprising the membrane 82 and the through-hole 800, can be considered a semi-rigid element. This angular sector 640 can include a rigid wall 80, similar to that of the other angular sectors 640 of the outer shell 64, while the membrane 82 provides flexibility. The through-hole 800 can be formed in this wall 80, and the membrane 82 can be attached to this wall 80 and cover the through-hole 800.

The through opening 800 and/or the membrane 82 can extend at least partially and circumferentially around the axis A. Alternatively, the through opening 800 and/or the membrane 82 can be annular, in particular when the corresponding shell (namely the shell comprising the through opening 800 and the membrane 82) is annular.

The membrane 82 defines a first compartment called injection 880, and a second compartment called compaction 882. The first compartment 880 opens into the cavity 60, and the second compartment 882 is separated from the cavity 60 by the membrane 82.

The membrane 82 can be made of an elastically deformable material, such as plastic or elastomer.

The membrane 82 can be configured to extend between a first position, called retracted, when the second compartment 882 is intended to be filled with a compaction fluid _FC , and a second position, called deployed or inflated, when the first compartment 880 is intended to be filled at least partially or totally with resin, in particular a second resin _R2 . FIG. 6 This schematically illustrates the first 880 and second 882 compartments, for example, when membrane 82 is in the second position. FIG. 7 schematically illustrates membrane 82 in first position with the second compartment 882 clearly visible and the first compartment 880 barely visible.

Tooling set 6 also includes:
- at least one first port 802, 804 which is connected to the first compartment 880 and which is configured to be connected to a resin source for the purpose of injecting resin into the first compartment 880, and
- at least one second port 884, 886 which is connected to the second compartment 882 and which is configured to be connected to a source of compaction fluid for the purpose of supplying the second compartment 882 with compaction fluid F _C.

The first port(s) 802, 804 can be formed directly in the corresponding hull (i.e. at least one of the hulls 62, 64 comprising the through opening 800 and the membrane 82).

The number of first ports 802 and 804 can be at least two. The first ports 802 and 804 can be located on two opposite sides of the through opening 800.

At least one first port 802, 804 can form a resin passage channel, in particular for the second resin _R2 . This passage channel, or in other words the first port 802, 804, can have an L-shaped curved shape in axial section ( FIG. 6 and 7). Thus, the first port 802, 804 can open, on the one hand, into the through opening 800 and the first compartment 880, and on the other hand, outside the tooling 6 in particular at the resin source.

In particular, at least one first port 802, 804 may include a first so-called inlet port 802 (or otherwise said for injecting resin into the first compartment 880) and a first so-called outlet port 804 (or otherwise said for draining excess resin from the first compartment 880 to the resin source).

The resin source may include a reservoir containing resin (in particular the second resin R ₂ as described below) and an injector to create a vacuum in the first compartment 880 if required, and/or for supplying resin from the source to the first compartment 880, and/or for draining excess resin from the first compartment 880 to the resin source.

In the example of figures 4 to 7, the first port(s) 802, 804 can be formed on the outer shell 64, and in particular the angular sector 640 comprising the through opening 800 and the membrane 82. In particular, the first inlet ports 802 and outlet ports 804 can extend on either side of the through opening 800.

At least one second port 884, 886 can form a passage hole for the compaction fluid. Thus, the second port 884, 886 can open, on the one hand, into the second compartment 882, and on the other hand, outside the tooling 6, in particular at the source of the compaction fluid.

The number of second ports 884, 886 can be at least equal to two.

In particular, at least one second port 884, 886 may include a second port called inlet 884 (or otherwise for injecting compaction fluid into the second compartment 882) and a second port called outlet 886 (or otherwise for draining the compaction fluid contained in the second compartment 882 to the compaction fluid source).

The compaction fluid source may include a reservoir containing the compaction fluid F _C and an injector to create a vacuum in the second compartment 882 if required, and/or for supplying compaction fluid F _C from the source to the second compartment 882, and/or for draining the compaction fluid from the second compartment 882 to the compaction fluid source.

As an example, the compaction fluid _FC can be water or oil.

Advantageously, tooling 6 can include a flange 84 ( FIG. 5 Preferably, the flange 84 can be located on the angular sector 640 comprising the through opening 800 and the membrane 82.

The membrane 82 can be permanently fixed to the flange 84 and/or to the shell 62, 64, for example by gluing.

Alternatively, the membrane 82 can be temporarily or removably fixed to the flange 84 and/or the shell 62, 64, for example by being compressed on its outer edges between the flange 84 and the shell 62, 64. In this configuration, the membrane 82 can be placed on the shell 62, 64, and the flange 84 can be placed on top of the assembly, in contact with the membrane 82 and the shell 62, 64. Thus, the flange 84 is fixed to the shell 62, 64, and the membrane 82 would be effectively wedged and fixed between the flange 84 and the shell 62, 64.

The flange 84 can cover the through opening 800 and can define the second compartment 882 with the membrane 82.

The flange 84 may include the second port(s) 884, 886.

Flange 84 can be made of metallic material.

This application will now describe an aeronautical part 5. This part 5 can be manufactured using the tooling 6 described above, particularly with reference to Figures 4 to 7.

Part 5 may comprise a single-piece body 50 (i.e., made from a single piece of material) consisting of two parts joined together,

A first 52 of these parts comprises the fibrous preform 520 embedded in a first polymeric matrix, and

a second 54 of these parts comprises a second polymeric matrix, the second part 54 having a fiber density of zero or less than that of the first part 52.

The second part 54 of part 5 can therefore correspond to a part enriched in RRA resin.

Aeronautical part 5 can therefore be made entirely of composite material.

Part 5, and in particular the first part 52, can be annular and the second part 54 can extend in projection on an external annular surface of the first part 52.

The second part 54 can be a stop or a protective covering of part or all of the external annular surface of the first part 52.

The invention applies generally and not limited to different types of aeronautical parts 5, in particular for an aircraft turbomachine 10.

The invention finds an advantageous but not exclusive application in annular parts 5 which can be an annular housing of the turbomachine 10.

For example, the FIG. 8 illustrates the aeronautical part 5 of annular shape and in which the first part 52 of this part is annular in shape and the second part 54 extends in projection on the external annular surface of this first part 52.

Part 5 can be obtained by a manufacturing process of the invention, as described below.

The present application will now describe a manufacturing process for aeronautical part 5 with reference to figures 9 to 12.

There FIG. 9 diagrams the different stages of implementation of the process of the invention, in which the optional stages are represented by dotted lines.

In general, the manufacturing process according to the invention makes it possible to produce the aeronautical part 5 using the tooling 6 of the invention.

The process may include the following steps:
(a) placement of the fibrous preform 520 in the cavity 60 of the tooling 6,
(c) densification of the fibrous preform 520 by injecting a first resin R ₁ into the cavity 60 of the tooling 6, so as to preform the first polymeric matrix,
(e) injection of a second resin R ₂ into the first compartment 880 of the tooling 6, so as to preform the second polymer matrix,
(g) simultaneous polymerization of the first R ₁ and second R ₂ resins, so as to form said first and second polymeric matrices.

The process may also include:
- a first compaction step (b) of the fibrous preform 520 which is carried out between steps (a) and (c), and which includes the injection of the compaction fluid F _C into the second compartment 882, and/or
- a second compaction step (f) of the fibrous preform 520 densified by the first resin R ₁ , which is carried out between steps (e) and (g) and which includes the injection of the compaction fluid F _C into the second compartment 882.

The process may further include, between steps (c) and (e) a step of emptying (d) the second compartment 882.

The process may include a step (i) of producing the fiber preform 520, this step (i) being carried out before step (a). In step (i), the fiber preform 520 may be produced by weaving fibers in two or three dimensions to form a woven fiber preform 520. Alternatively, step (i) may be carried out by draping and layering several fibers to form a laminated fiber preform 520.

The 520 fibrous preform is said to be dry, meaning that it is not pre-impregnated with resin.

In step (a), the fibrous preform 520 can be placed in the cavity 60 formed either on the inner shell 62 or on the outer shell 64, or between the inner shell 62 and outer shell 64. In this way, the fibrous preform 520 is enclosed in the tooling 6. The cavity 60 can have a shape complementary to that of the fibrous preform 520.

At step (b), once tooling 6 is closed, the compaction fluid F _C can be injected into the second compartment 882 through the second port 884 of tooling 6.

Step (b) may also include vacuuming the tooling 6 to trap the fibrous preform 520 largely between the shells 62, 64 and locally at the membrane 82. In this way, the membrane 82 can apply a compaction force to the fibrous preform 520 to press it into the cavity 60. The vacuuming can be achieved by removing the air from the cavity 60 and the first compartment 880 through the first port(s) 802, 804, as illustrated by the dashed arrows on the FIG. 10 This vacuuming can be carried out simultaneously with the injection of the compaction fluid _FC .

At step (c), the first resin R ₁ can be injected through the first or second injection port of the shell 62, 64. The quantity of first resin R ₁ injected can correspond to the volume of the fibrous preform 520 to be impregnated and to the desired TVF and TVM rates in the final part 5 (excluding second part 54).

For example, the FIG. 10 illustrates both the second compartment 882 filled with the compaction fluid F _C so as to retract the membrane 82 in support of the fibrous preform 520, and the first resin R ₁ injected into the cavity 60 containing the fibrous preform 520.

The first _R1 resin can be of the thermosetting type. For example, the first _R1 resin can be an epoxy.

After impregnation of the fibrous preform 520 by the first resin R ₁ , the tooling 6 can be heated to densify the fibrous preform 520 by polymerization and hardening of the first resin R ₁ .

The heating of tooling 6 can be carried out at a predetermined temperature between 100°C and 200°C and for a predetermined duration between 10h and 20h (hour).

This predetermined temperature and predetermined heating time allow for partial polymerization of the first resin R ₁ .

The polymerization rate of the first resin R ₁ can be between 50% and 70% at step (c).

At the end of step (c), the fibrous preform 520 can therefore be embedded in the first resin R ₁ which has a viscous and gelled form.

In step (d), the compaction fluid Fc contained in the second compartment 882 can be emptied, for example, through the second port 886. This releases the compaction force applied by the membrane 82 on the fibrous preform 520, thus enabling step (e) to be carried out. The emptying of the second compartment 882 is illustrated by an arrow on the FIG. 11 .

At step (e), the second resin R ₂ can be injected into the first compartment 880 of the tooling 6 through the first port 802. The quantity of second resin R ₂ injected can correspond to the thickness of the second part 54 to be formed and the desired TVM rates in the final part 5 (excluding the first part 52).

For example, the FIG. 11 illustrates both the emptying of the second compartment 882 so as to deploy the membrane 82 in a direction opposite to the cavity 60, and the injection of the second resin R ₂ into the first compartment 880.

The second resin R ₂ can thus at least partially cover the fibrous preform 520 densified with the first resin R ₁ of step (c).

The second resin _R2 can be identical to the first resin _R1 .

The second resin _R2 can be of the thermosetting type. For example, the second resin _R2 can be an epoxy.

At step (f), once the first compartment 880 is filled with the first resin R ₁ and the first port(s) 802, 804 are closed, the compaction fluid Fc can be injected into the second compartment 882 through the second port 884 of the tooling 6. The compaction fluid allows a compaction force to be applied to the first compartment 880 filled with the first resin R ₁ to press it against the fibrous preform 520.

The volume of the second compartment 882 filled with the compaction fluid F _C in this step (f) may be less than that of step (b). Indeed, the membrane 82 is deployed and the first compartment 880 is filled with the first resin R ₁ , thus reducing the volume of the second compartment 882 filled with the compaction fluid F _C in step (f).

For example, the FIG. 12 illustrates the first compartment 880 filled with the first resin R ₁ and the injection of the compaction fluid F _C into the second compartment 882.

In step (g), the tooling 6 can be heated to simultaneously polymerize and harden the first resin R ₁ with the fibrous preform 520 in the cavity 60 and the second resin R ₂ in the first compartment 880. During this step (g), covalent bonds can be created at the interface between the first R ₁ and second R ₂ resins to form a homogeneous crosslinking point network.

The heating of tooling 6 can be carried out at a predetermined temperature between 100°C and 200°C and for a predetermined duration between 10h and 20h (hour).

This predetermined temperature and predetermined heating time allows for partial polymerization of the first resin R ₁ .

The polymerization rate of the first resin R ₁ and the second resin R ₂ can be 100% at the end of step (g).

Claims (14)

Tooling (6) for manufacturing an aeronautical part (5), in particular for an aircraft turbomachine (10),
the tooling (6) comprising at least two rigid shells (62, 64) which are assembled to define between them a cavity (60), this cavity (60) being intended to receive a fibrous preform (520),
characterized in that at least one of the shells (62, 64) comprises a through opening (800), and an elastically deformable membrane (82) which extends at the level of this opening and which defines a first compartment called injection (880), which opens into the cavity (60), and a second compartment called compaction (882) which is separated from the cavity (60) by the membrane (82),
and in that the tooling (6) further comprises at least one first port (802, 804) which is connected to the first compartment (880) and which is configured to be connected to a resin source for the purpose of injecting resin into said first compartment (880), and at least one second port (884, 886) which is connected to the second compartment (882) and which is configured to be connected to a compaction fluid source for the purpose of supplying the second compartment (882) with compaction fluid. Tooling according to claim 1, in which a flange (84) covers said through opening (800) and defines said second compartment (882) with said membrane (82). Tooling according to claim 2, wherein the flange (84) comprises said at least one second port (884, 886). Tooling according to any one of the preceding claims, wherein the number of second ports (884, 886) is at least equal to two. Tooling according to any one of the preceding claims, wherein said at least one first port (802, 804) is formed directly in at least one of the hulls (62, 64) comprising the through opening (800). Tooling according to any one of the preceding claims, wherein the number of first ports (802, 804) is at least equal to two, and the first ports (802, 804) are located on two opposite sides of the through opening (800). Tooling according to any one of the preceding claims, wherein the number of shells (62, 64) is greater than two. Tooling according to any one of the preceding claims, wherein the shells (62, 64) comprise two annular shells, respectively internal (62) and external (64), and two end annular shells (66, 68), the cavity (60) defined by these shells (62, 64) being annular. Tooling according to claim 8, wherein the opening and the membrane (82) are located on the outer shell (64), and in particular on an angular sector (640) of this outer shell (64). Method for manufacturing an aeronautical part (5), in particular for an aircraft turbomachine (10),
the part (5) comprising a one-piece body (50) comprising two parts joined together, a first (52) of these parts comprising a fibrous preform (520) embedded in a first polymeric matrix, and a second (54) of these parts comprising a second polymeric matrix, the second part (54) having a fiber density of zero or less than that of the first part (52),
characterized in that this part (5) is made using tooling according to any one of the preceding claims. A manufacturing process according to claim 10, wherein the process comprises the following steps:
(a) placement of the fibrous preform (520) in the cavity (60) of the tooling (6),
(c) densification of the fibrous preform (520) by injecting a first resin into the cavity (60) of the tooling (6), so as to preform said first polymeric matrix,
(e) injection of a second resin into the first compartment (880) of the tooling (6), so as to preform said second polymeric matrix,
(g) simultaneous polymerization of the first and second resins, so as to form said first and second polymeric matrices. A manufacturing process according to claim 11, wherein the process further comprises:
- a first compaction step (b) of the fibrous preform (520) which is carried out between steps (a) and (c), and which includes the injection of the compaction fluid into the second compartment (882), and
- a second compaction step (f) of the fibrous preform (520) densified by the first resin, which is carried out between steps (e) and (g) and which includes the injection of the compaction fluid into the second compartment (882). Manufacturing process according to claim 12, wherein the process further comprises, between steps (c) and (e) a step of emptying (d) the second compartment (882). Aeronautical part (5) for an aircraft turbomachine (10), the part (5) being obtained by the manufacturing process according to any one of claims 10 to 13, the part (5) comprising the body (50) comprising the first part (52) with the fibrous preform (520) embedded in the first polymeric matrix, and the second part (54) comprising the second polymeric matrix and having a fiber density of zero or less than that of the first part (52), the part (5) being annular and said second part (54) being projecting on an external annular surface of the first part (52).