Method for producing a component from a composite material with a reinforced matrix and device for carrying out the method

Description

Technical Field

[0001] The invention relates to the manufacture of a part made of composite material comprising a fibrous reinforcement based on carbon fibers densified by a matrix.

[0002] More specifically, it concerns the manufacture of composite material parts for turbomachines from a fibrous structure obtained by three-dimensional weaving of carbon fibers and densified by a reinforced matrix. Prior art

[0003] The production of composite material parts for turbomachines, such as blades for gas turbine engines, has already been proposed. Reference may be made, for example, to document EP 1 526 285, which describes the manufacture of a fan blade by producing a fiber preform by three-dimensional (3D) weaving and densifying the preform with an organic matrix.

[0004] 3D weaving here means a multi-layer weave using several layers of weft threads and several layers of warp threads, with warp threads binding together weft threads of different layers.

[0005] Typically, these parts made of organic matrix composite (OMC) material are manufactured from a fibrous structure obtained by 3D weaving, this fibrous structure being placed in a closed mold before injecting a resin inside it at least until the preform is stiffened (or consolidated).

[0006] It has been shown that in the event of damage to composite parts obtained in this way, the first level of damage is in the resin. However, this first level of damage is a design parameter of the part which is fundamental because it is directly linked to the capacity of the material to withstand loads throughout its lifetime.

[0007] Increasing the level of first damage to the part therefore makes it possible either to increase the service life of the part or to make the part lighter by allowing it to be designed with a higher loading level.

[0008] To this end, to increase the level of first damage to the part, it is possible to modify the chemical formulation of the resin used to reinforce it. However, this possibility is limited by the fact that it requires a complete characterization of the manufactured composite material, which is time-consuming and expensive. In addition, this characterization of the composite material is generally carried out to the detriment of other properties of the resin (temperature resistance, etc.).

[0009] Reference is also made to document WO2015 / 184151 A1. Statement of the invention

[0010] The object of the invention is therefore to propose a method for manufacturing a part made of composite material which makes it possible to increase the level of first damage to the part without modifying the chemical formulation of the resin.

[0011] This aim is achieved by means of a method for manufacturing a part made of composite material comprising a fibrous reinforcement based on carbon fibers densified by a matrix, the method successively comprising the production of a fibrous structure by multi-layer three-dimensional weaving, the placement in a closed mold of the fibrous structure, and the injection into the mold of a resin, and in which, in accordance with the invention, during the weaving of the fibrous structure, the method further comprises the projection of carbon nanoparticles onto the carbon fibers.

[0012] The present invention is remarkable in that it provides for strengthening the resin used by adding carbon nanoparticles (such as carbon nanotubes or graphene) during the weaving of the fibrous structure. This addition is thus carried out without modifying the chemical formulation of the resin. It also avoids forming pockets of pure resin within the material. On the contrary, the invention makes it possible to place carbon nanoparticles around each carbon fiber in order to strengthen them.

[0013] In this way, the nanoparticles added during the weaving of the fibrous structure allow the resin to be reinforced without disturbing the woven structure and without changing the chemical formulation of the resin. As a result, the level of first damage to the part can be increased without this being at the expense of other properties of the resin.

[0014] The weaving of the fibrous structure is carried out, according to the invention, using a loom. In this case, the projection of carbon nanoparticles onto the carbon fibers is carried out at a shed opening created by the lifting of certain carbon threads relative to the others.

[0015] Similarly, the process can also include spraying carbon nanoparticles onto the fibrous structure before it is placed in the mold. This spraying avoids filtration phenomena by directly positioning the nanoparticles before the injection step. The level of initial damage to the part is further increased.

[0016] The invention also relates to a device for implementing the method as defined above, comprising a loom for producing a fibrous structure by multi-layer three-dimensional weaving, the loom comprising: a harness consisting of a weaving board and a plurality of heddles into which warp threads are inserted, each heddle being driven by a vertical oscillating movement to lift certain warp threads in order to create a shed opening allowing the introduction of weft threads; a comb provided with teeth to allow the distribution of the warp threads and the packing of the weft threads after their passage between the warp threads; and means for projecting carbon nanoparticles mounted on the comb.

[0017] The projection means may comprise an injection nozzle mounted on a frame of the comb and which is connected by a pipe to a reservoir of carbon nanoparticles.

[0018] Alternatively, the projection means can be formed by comb teeth which are hollow and which are connected to a reservoir of carbon nanoparticles.

[0019] Alternatively, the projection means comprise an injection nozzle mounted on bars for holding the fibrous structure at the weaving point and which is connected by a pipe to a reservoir of carbon nanoparticles. Brief description of the drawings

[0020] [ Fig. 1 ] There figure 1 is a schematic view showing a loom for implementing the method according to the invention. Description of the embodiments

[0021] The invention relates to a method for manufacturing a part made of composite material, in particular a turbomachine part such as, for example, a fan blade, comprising a fibrous reinforcement based on carbon fibers densified by an organic matrix.

[0022] In a known manner, such a method successively comprises the production of a fibrous structure by multi-layer three-dimensional weaving, the placement in a closed mold of the fibrous structure, and the injection into the mold of a resin, characterized in that during the weaving of the fibrous structure

[0023] Three-dimensional (3D) weaving is understood herein to mean a multi-layer weave using several layers of weft yarns and several layers of warp yarns, with warp yarns binding together weft yarns of different layers. Different types of 3D weave weaves may be used, for example interlock, multi-satin, multi-plain, multi-twill weaves. Reference may be made in particular to WO 2006 / 136755, the contents of which are incorporated herein by reference.

[0024] The deposition of the matrix in the fibrous structure thus formed is carried out while maintaining the structure in the mold at least until the structure stiffens (or consolidates).

[0025] The matrix is ​​of a nature chosen according to the intended application, for example an organic matrix obtained in particular from a polymer matrix precursor resin such as an epoxy, bismaleimide or polyimide resin, or a carbon matrix or a ceramic matrix.

[0026] In the case of an organic matrix, the fibrous structure is impregnated with a composition containing the matrix precursor resin, before shaping in a tool, or after shaping, the impregnation being carried out in the latter case for example by infusion or by an RTM type process (for "Resin Transfer Moulding").

[0027] In the case of a carbon or ceramic matrix, densification may be achieved by chemical vapor infiltration, or CVI (for "Chemical Vapor Infiltration") or by impregnation with a liquid composition containing a carbon or ceramic precursor resin and thermal pyrolysis or ceramization treatment of the precursor, these processes being well known per se.

[0028] The 3D weaving of the fibrous structure is carried out using a loom such as the one illustrated in the figure 1 .

[0029] In a known manner (see for example publication EP 1 526 285 A1), such a loom 10 is equipped with a Jacquard mechanism 11 supported by a superstructure not shown in the figure 1 .

[0030] The loom 10 also comprises a harness 20 consisting of a weaving board 21 and control threads or heddles 22, each heddle 22 being connected at one end to a control hook 12 of the Jacquard mechanism 11 and at the other end to a return spring 13 fixed to the frame 14 of the loom 10.

[0031] Each heddle 22 comprises an eyelet 23 crossed by a warp thread 30. The heddles 22 and their associated eyelet 23 are driven by a substantially vertical oscillating movement represented by the double arrow F under the tensile forces exerted respectively by the control hooks 12 and the return springs 13. The heddles 22 make it possible to lift certain warp threads 30 and thus create a shed 15 allowing the introduction of weft threads 31 using a shuttle (not shown in the figure). figure 1 ).

[0032] The rails 22 are distributed spatially according to the position of the holes 210 of the joining board 21, that is to say according to a plurality of columns 211 and lines 212.

[0033] The density of the holes 210 in the weaving board corresponds to the density of the fabric to be made, that is to say that we find in the weaving board a spacing between each column of holes equivalent to that present between each column of warp in the fabric to be made.

[0034] The loom also comprises a comb 40 which is positioned at the level of the shed 15 in order to allow the distribution of the warp threads 30 and the packing of the weft thread 31 after each shuttle passage. In a known manner, it consists of a frame 401 carrying a series of fine taut cables 402 forming the teeth of the comb.

[0035] According to the invention, it is intended to increase the level of first damage to the composite material part manufactured using such a process, without modifying the chemical formulation of the resin used.

[0036] To this end, the invention provides for the projection of carbon nanoparticles (of the carbon nanotube or graphene type for example) onto the carbon fibers during the weaving of the fiber structure.

[0037] In practice, it is particularly advantageous to take advantage of the opening of the shed 15 created by the lifting of certain warp threads 30 by the heddles 22. Indeed, the shed 15 is an angular passage space which particularly facilitates the projection of carbon nanoparticles onto the carbon fibers of the fibrous structure.

[0038] As shown in the figure 1, for example, an injection nozzle 50 could be positioned on the frame 401 of the comb 40 of the loom, this injection nozzle being directed towards the shed opening to reach a maximum of carbon fibers 30, 31.

[0039] In this configuration, the injection nozzle is advantageously connected to a reservoir 51 containing carbon nanoparticles via a pipe 52 running along the frame 401 of the comb.

[0040] In an implementation variant not shown, it will be possible to use teeth 402 of the comb which are hollow in order to circulate the carbon nanoparticles therein from the reservoir 51. In this variant, the presence of the injection nozzle and the pipe is therefore replaced by these hollow teeth.

[0041] In another implementation variant not shown, it is possible to use a carbon nanoparticle injection nozzle which is mounted at the level of the holding bars of the fibrous structure which typically allow the fabric to be held at the weaving point. This variant thus makes it possible to perfectly localize the projection of nanoparticles.

[0042] Furthermore, the level of first damage to the composite material part can be further increased by adding to the previously described carbon nanoparticle injection process additional manipulations described below.

[0043] Still with the aim of further increasing the level of first damage, it can also be planned, as an alternative or in addition to the previous manipulation, to project carbon nanoparticles directly onto the fibrous structure before its placement in the mold. This manipulation makes it possible to avoid the filtration phenomena mentioned previously.

Claims

1. A process for manufacturing a composite material component comprising a fiber reinforcement based on carbon fibers densified by a matrix, the process comprising successively producing a fiber structure by multilayer three-dimensional weaving, placing the fiber structure in a closed mold, and injecting a resin into the mold, wherein during weaving of the fiber structure, the process further comprises spraying carbon nanoparticles onto the carbon fibers, the weaving of the fiber structure being performed using a loom, and the spraying of carbon nanoparticles onto the carbon fibers being performed at a shed opening (15) created by lifting certain carbon threads from others.

2. The process as claimed in claim 1, further comprising spraying carbon nanoparticles onto the fiber structure prior to placing it in the mold.

3. A device for carrying out the process as claimed in any one of claims 1 or 2, comprising a loom (10) for producing a fiber structure by multilayer three-dimensional weaving, the loom comprising: a harness (20) consisting of a stuffing board (21) and a plurality of heddles (22) into which warp threads (30) are inserted, each heddle being animated by a vertical oscillation movement to lift certain warp threads in order to create a shed opening (15) allowing weft threads (31) to be inserted; a comb (40) provided with teeth (402) for distributing the warp threads and compacting the weft threads after they have passed between the warp threads; and carbon nanoparticle spraying means (50) mounted on the comb.

4. The device as claimed in claim 3, wherein the spraying means comprise an injection nozzle (50) mounted on a frame (401) of the comb and which is connected by a pipe (52) to a reservoir (51) of carbon nanoparticles.

5. The device as claimed in claim 4, wherein the spraying means are formed by comb teeth that are hollow and are connected to a reservoir of carbon nanoparticles.

6. The device as claimed in claim 4, wherein the spraying means comprises an injection nozzle mounted on bars holding the fiber structure at the weaving point and which is connected by a pipe to a reservoir of carbon nanoparticles.