Method for manufacturing a fibrous structure with ply separation in a deployed portion and resulting fibrous structure
By separating deployment portions into multiple plies in the fibrous structure, the method addresses angular variations and detachment issues, enhancing filling and mechanical properties in turbine ring sectors.
Patent Information
- Application Number
- FR2023010832
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-10-10
- Publication Date
- 2026-03-06
- Estimated Expiration
- 2043-10-10
AI Technical Summary
Three-dimensional weaving of fibrous structures results in angular variations and shearing of weft yarn columns, leading to detachment and misalignment issues, which affect the mechanical properties and infiltration of the preform, particularly in turbine ring sectors.
The method involves separating deployment portions of the fibrous structure into multiple independent plies through additional unbindings, each ply comprising layers of warp and weft yarns woven together, reducing shear forces and improving positioning accuracy.
This approach reduces angular variations and detachment, enhances filling of radii, and improves mechanical properties by minimizing misalignment and ensuring better infiltration during preform formation.
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Abstract
Description
Title of the invention: Method for manufacturing a fibrous structure with ply separation in a portion of the unfolded portion and resulting fibrous structure technical field
[0001] The present invention relates to the production of parts in composite material and more particularly to the production by three-dimensional (3D) weaving of fibrous reinforcement structures for such parts. Previous technique
[0002] One application of the invention is the production of parts made of structural composite materials, that is, structural parts with fiber reinforcement and densified by a matrix, such as parts made of organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC). Organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC) materials replace parts made of metallic materials in certain parts of turbomachinery. Their use contributes to optimizing aircraft performance, particularly by improving turbomachine efficiency and reducing the overall mass of the turbomachine, significantly reducing harmful emissions (CO, CO2, NOx, etc.) and fuel consumption.
[0003] The invention relates more particularly to fibrous reinforcement structures obtained by three-dimensional (3D) weaving and which include one or more deployment portions, i.e. one or more parts intended to be deployed during the shaping of a fibrous structure.
[0004] An example of this type of fibrous structure is that used to form the fibrous reinforcement of a turbine ring sector made of composite material, as notably disclosed in document US2012027572.
[0005] Figure 1 illustrates a fibrous structure 10 intended to form the fibrous reinforcement of a turbine ring sector made of composite material. The structure 10 is obtained by three-dimensional weaving between a plurality of warp yarn layers and a plurality of weft yarn layers, the warp yarns extending along a longitudinal direction DL and the weft yarns extending along a transverse direction DT. The weft yarns are woven into a plurality of columns represented here by lines CT. The weft yarn columns CT are spaced from each other along the longitudinal direction DL, the weft yarns of each weft yarn column being juxtaposed within the thickness of the fibrous structure along an overlapping direction DS1 perpendicular to the longitudinal direction DL.
[0006] The structure 10 comprises a lower part 12 intended to form the base of the ring sector, and an upper part 14 connected to the lower part 12 by a central portion 16. The upper part 14 comprises two deployment portions 141 and 142 located at opposite lateral ends of the central portion 16 and which are not connected with the lower part 12. In other words, the fibrous structure 10 comprises two unbundling zones 18 at two opposite edges in a transverse direction of the structure 10, so as to leave two free deployment portions.
[0007] Figure 2 illustrates the shaping of the fibrous structure 10 by folding the deployment portions 141 and 142 at 90° towards the central portion 16 so as to form, after densification, attachment flanges for the ring sector on a ring support structure in a turbine. After folding, the overlap direction of the frame wires of the frame columns present in the deployment portions 141 and 142 is modified. More specifically, the overlap directions DSui and DSi42 of the frame wires of the frame columns of the deployment portions 141 and 142 respectively exhibit a significant angular variation with respect to their initial overlap direction DSi0. The frame columns in the deployment portions 141 and 142 have a shear angle [3] that is between 45° and 60°.This angular variation results from the shear forces exerted in the deployment portions 141 and 142 during their deployment, the path at the level of the internal radius R1NT being shorter than the path of the external radius Rext-.
[0008] This angular offset in the weft yarn columns causes a detachment in the fibrous structure at the level of a connecting radius, here mainly the internal radius R1NT, as well as a lack of material at the level of the external radius Rext, which is detrimental to the finished part because it creates an area devoid of fibrous reinforcement.
[0009] Furthermore, due to the three-dimensional weaving, the angular offset causes shearing of the weft yarn columns and, consequently, misalignment in the relevant portions which can disrupt the infiltration of the resulting preform and modify the mechanical properties initially defined. Description of the invention
[0010] It is therefore desirable to have a solution for the production of fibrous structures that do not present the aforementioned disadvantages.
[0011] To this end, the present invention proposes a method for manufacturing a fibrous structure by weaving between a plurality of layers of warp yarns and a plurality of layers of weft yarns, the warp yarns extending along a longitudinal direction, the weft yarns extending along a transverse direction, the weft yarns being woven in a plurality of columns spaced apart along the longitudinal direction, the weft yarns of each column of weft yarns being juxtaposed in the fibrous structure along a thickness direction of said fibrous structure, the fibrous structure comprising a first part in which all the layers of weft yarns are linked together by warp yarns of the plurality of warp layers by three-dimensional or multilayer weaving and at least a second part adjacent to the first part along the longitudinal direction, the second part comprising a base portion and a spread portion separated from each other by a first unbinding extending along the longitudinal direction in the second part of the fibrous structure from a bottom of unbinding adjacent to the first part of the fibrous structure,characterized in that said unfolded portion of said at least a second part of the fibrous structure is separated along the thickness direction into at least first and second unbound plies by a second unbound extending along the longitudinal direction in the second part of the fibrous structure from a unbound bottom adjacent to the first part of the fibrous structure, and in that the first and second plies each comprise at least one layer of warp yarns from the plurality of warp yarn layers of the first part of the fibrous structure and at least one layer of weft yarns, the warp yarns of said at least one layer of warp yarns being woven with the weft yarns of said at least one layer of weft yarns.
[0012] This forms a fibrous structure comprising one or more unfolded portions, each divided into a plurality of independent, or unbound, plies. This allows for a relaxation of the stresses compared to the case where the unfolded portion(s) are made of a single 3D woven block. The shear forces applied in the unfolded portion(s) are thus significantly reduced, which notably improves the filling of the internal and external radii. The formation of unbound plies in the unfolded portion(s) also improves the positioning accuracy during preform formation, as positioning each plie is easier than positioning a single 3D woven block.
[0013] According to a particular feature of the process of the invention, the first and second plies each comprise at least three layers of warp yarns from the plurality of layers of warp yarns from the first part of the fibrous structure and at least three layers of weft yarns, said at least first and second plies being woven by three-dimensional or multi-layer weaving of the warp yarns from said at least three layers of warp yarns with the weft yarns from said at least three layers of weft yarns.
[0014] Since each fold is formed by 3D weaving, the properties of the 3D weaving are preserved in the deployment portion(s), each ply thus exhibiting in particular very good resistance to delamination.
[0015] According to another particular feature of the method of the invention, each plies comprise at most four layers of warp yarns from the plurality of warp yarn layers of the first part of the fibrous structure and four layers of weft yarns. This further reduces the shear stresses in each plies of the relevant unfolded portion.
[0016] According to another particular feature of the process of the invention, the pleats are each woven according to one of the following multilayer weaves: interlock, multi-satin, multi-twill and multi-plain.
[0017] The invention also relates to a method for manufacturing a part made of composite material comprising:
[0018] - the weaving of a fibrous structure according to the weaving process according to the invention,
[0019] - shaping the fibrous structure by folding the portion or portions of folding to obtain a fibrous preform,
[0020] - the densification of the fibrous preform by a matrix.
[0021] The method for manufacturing a part made of composite material according to the invention can be used for the manufacture of a turbine ring sector, a stiffener or a fixed or moving turbomachine blade.
[0022] The invention also relates to a fibrous structure comprising a plurality of layers of warp yarns and a plurality of layers of weft yarns, the warp yarns extending along a longitudinal direction, the weft yarns extending along a transverse direction, the fibrous structure comprising a plurality of columns of weft yarns spaced apart along the longitudinal direction, the weft yarns of each column of weft yarns being juxtaposed in the fibrous structure along a thickness direction of said fibrous structure, the fibrous structure comprising a first part in which all the layers of weft yarns are linked together by warp yarns of the plurality of warp layers by a three-dimensional or multi-layered weave and at least a second part adjacent to the first part along the longitudinal direction,the second part comprising a base portion and a deployment portion separated from each other by a first unbinding extending along the longitudinal direction in the second part of the fibrous structure from a bottom of unbinding adjacent to the first part of the fibrous structure, characterized in that said deployment portion of said at least a second part of the fibrous structure is separated along the thickness direction into at least the first and second unbound plies by a second unbinding extending along the longitudinal direction in the second, part of the fibrous structure from a debinding background adjacent to the first part of the fibrous structure and in that the first and second plies each comprise at least one layer of warp yarns from the plurality of layers of warp yarns of the first part of the fibrous structure and at least one layer of weft yarns, the warp yarns of said at least one layer of warp yarns being woven with the weft yarns of said at least one layer of weft yarns.
[0023] According to a particular feature of the fibrous structure of the invention, the first and second plies each comprise at least three layers of warp yarns from the plurality of layers of warp yarns of the first part of the fibrous structure and at least three layers of weft yarns, said at least first and second plies being woven by three-dimensional or multi-layer weaving of the warp yarns of said at least three layers of warp yarns with the weft yarns of said at least three layers of weft yarns.
[0024] According to another particular feature of the fibrous structure of the invention, the plies each comprise at most four layers of warp yarns from the plurality of layers of warp yarns of the first part of the fibrous structure and four layers of weft yarns.
[0025] According to another particular feature of the fibrous structure of the invention, the plies are each woven according to one of the following multilayer weaves: interlock, multi-satin, multi-twill and multi-plain.
[0026] The invention further relates to a part made of composite material comprising a fibrous reinforcement densified by a matrix characterized in that the fibrous reinforcement comprises a fibrous structure according to the invention.
[0027] According to a particular feature of the part of the invention, this corresponds to a turbine ring sector, a stiffener or a fixed or moving turbomachine blade. Brief description of the drawings
[0028] [Fig-1] Fig. 1 is a schematic perspective view of a fibrous structure according to prior art,
[0029] [Fig.2] The [Fig.2] is a schematic front view showing the structure of the [Fig.1] after formatting,
[0030] [Fig.3] Fig.3 is a schematic perspective view of a type loom Jacquard used to manufacture a fibrous structure according to the invention.
[0031] [Fig.4] [Fig.4] is a schematic front view of a fibrous structure in accordance with one embodiment of the invention,
[0032] [Fig.5] The [Fig.5] is a weave pattern of the fibrous structure of the [Fig.4]
[0033] [Fig.6] The [Fig.6] is a schematic front view of the fibrous structure of the [Fig.4] after shaping. Description of the implementation methods
[0034] The invention applies generally to the production of fibrous structures or fabrics by three-dimensional (3D) or multilayer weaving between layers of warp yarns and layers of weft yarns, the structure comprising at least one portion intended to be deployed during its shaping.
[0035] The term “three-dimensional weave” or “3D weave” refers to a weaving method in which at least some of the weft yarns interlock with warp yarns over several layers of warp yarns, or vice versa. An example of a three-dimensional weave is the so-called “interlock” weave. “Interlock” refers to a weave structure in which each layer of warp yarns interlocks with several layers of weft yarns, with all the yarns in the same warp column having the same movement within the plane of the weave.
[0036] The term "multilayer weave" here refers to a 3D weave with several weft layers, the basic weave of each layer being equivalent to a conventional 2D fabric weave, but with certain points of the weave that link the weft layers together. Known examples of multilayer weaves that can be used here include those described in US2007007386 and US2009186547.
[0037] The wires used here may include carbon fiber wires or ceramic fiber wires such as silicon carbide (SiC) fibers, the invention not being limited to these types of wires only.
[0038] Fig. 3 illustrates a loom 100 equipped with a Jacquard mechanism 101 supported by a superstructure not shown in Fig. 1. The loom 100 also includes a harness 110 consisting of a heddle board 111 and control threads or heddles 113, each heddle 113 being connected at one end to a control hook 1010 of the Jacquard mechanism 101 and at the other end to one of the return springs 102 fixed to the frame 103 of the loom 100. Each heddle 113 includes an eyelet 114 through which a warp thread 203 passes. The heddles 113 and their associated eyelet 114 extend into an area in which the heddles 113 and the eyelets 114 are set in a substantially vertical oscillating motion represented by the double arrow F. The heddles 113 are subjected to tensile forces exerted respectively by the control hooks 1010 and by the return springs 102.The heddles 113 allow certain warp yarns 203 to be lifted according to a defined weaving program. By lifting certain warp yarns 203, the heddles 113 create a shovel that allows the introduction of weft yarns 204 for 3D or multilayer weaving of a fibrous texture 200 in the form of a strip or ribbon. The warp yarns 201 are... organized into a plurality of warp threads Cl to Cn. A reed 120, located upstream of the sheaf, packs each introduced weft thread by moving from upstream to downstream until it reaches a position corresponding to the closing of the sheaf. The warp threads 203 are fed from bobbins arranged on a creel (not shown in [Fig. 3]) upstream of the Jacquard mechanism 101 of the loom 100.
[0039] A method for manufacturing a fibrous structure 200 according to an embodiment is now described. In the example described here, the fibrous structure 200 is intended to form the fibrous reinforcement of a turbine ring sector made of composite material. As illustrated in [Fig. 4], the fibrous structure 200, once woven, comprises a first portion 230, corresponding here to a central portion of the fibrous structure; a second portion 240, adjacent to the first portion 230 along the longitudinal direction DL and forming here a first end of the fibrous structure 200; and a third portion 250, also adjacent to the first portion 230 along the longitudinal direction DL and forming here a second end of the fibrous structure 200. In the central portion 230, all the weft yarn layers are linked together by warp yarns of the plurality of warp layers by 3D or multilayer weaving.
[0040] The fibrous structure 200 has a lower portion 210 intended to form the base of the ring sector, and an upper portion 220 connected to the lower portion 210 by the first portion 230. The second portion 240 comprises a base portion 241 present in the lower portion 210 of the fibrous structure 200 and a deployment portion 242 present in the upper portion of the structure adjacent to a first lateral end 231 of the first portion 230. Similarly, the third portion 250 comprises a base portion 251 present in the lower portion 210 of the fibrous structure 200 and a deployment portion 252 present in the upper portion of the structure adjacent to a second lateral end 232 of the first portion 230.
[0041] The deployment portions 242 and 252 are not connected respectively to the base portions 241 and 251 of the lower part 210, two unlinkages 260 and 261 being created during weaving in the fibrous structure at two opposite edges so as to leave the deployment portions 242 and 252 free. The two unlinkages 260 and 261 each extend along the longitudinal direction DL into the second and third parts 240 and 250 respectively of the fibrous structure 200 from a unlinkage base 2600, 2610 adjacent to the first part 230 of the fibrous structure. The unlinkages 260 and 261 also extend in the transverse direction DT.
[0042] According to the invention, each deployment portion is separated into several independent folds by additional unbindings, each fold comprising at least one layer of warp yarns from the first part of the fibrous structure and at least a layer of weft yarns, the warp yarns of the layer(s) of warp yarns being woven with the weft yarns of the layer(s) of weft yarns. When a ply comprises a layer of warp yarns and a layer of weft yarns, the warp and weft yarns are woven together in a two-dimensional weave.
[0043] When a ply comprises two layers of warp yarns and / or two layers of weft yarns, the warp and weft yarns are woven together in a multi-layer weave.
[0044] When a ply comprises at least three layers of warp yarns and at least three layers of weft yarns, the warp yarns and weft yarns are preferably woven together by 3D or multilayer weaving.
[0045] There is therefore a continuity of warp yarns in the first, second and third parts 230, 240 and 250 of the fibrous structure and in particular in the independent folds of the deployment portions ensuring good resistance of a fibrous reinforcement formed from the fibrous structure of the invention.
[0046] In the example described here, the deployment portion 242 of the second part 240 of the fibrous structure 200 is separated into four independent folds 2420, 2421, 2422, and 2423 by three unties 270, 271, and 272, each extending along the longitudinal direction D1 into the second part 240 of the fibrous structure 200, respectively, from the unties 2700, 2710, and 2720 adjacent to the first part 230 of the fibrous structure. The unties 270, 271, and 272 also extend in the transverse direction DT. The deployment portion 252 of the second part 250 of the fibrous structure 200 is separated into four independent folds 2520, 2521, 2522 and 2523 by three unlinks 280, 281 and 282 extending each along the longitudinal direction DL into the third part 250 of the fibrous structure 200 respectively from the unlink bottoms 2800, 2810 and 2820 adjacent to the first part 230 of the fibrous structure.The disjunctions 280, 281 and 282 also extend in the transverse direction DT.
[0047] The fibrous structure according to the invention can in particular be made by 3D or multilayer weaving following an interlock, multi-satin, multi-plain or multi-twill weave.
[0048] The term "multi-satin weave or fabric" herein refers to a 3D or multi-layered weave with several layers of weft yarns, the basic weave of each layer being equivalent to a classic satin weave but with certain points of the weave that bind the layers of weft yarns together. The term "multi-plain weave or fabric" herein refers to a 3D or multi-layered weave with several layers of weft yarns, the basic weave of each layer being equivalent to a classic plain weave but with certain points of the weave that bind the layers of weft yarns together. The term "multi-twill weave or fabric" herein refers to a 3D weave with several layers of weft yarns, the basic weave of each layer being equivalent to a classic twill weave but with certain points of the weave that link the layers of weft yarns together.
[0049] By way of non-limiting example, the fibrous texture according to the invention can be achieved by 3D weaving following a multi-satin weave as shown in [Fig.5].
[0050] Figure 5 shows a multi-satin armor pattern corresponding to a part of the first part 230 and third part 250 of the fibrous structure 200. In this example, the fibrous structure 200 comprises twenty-eight layers of warp yarns CCi to CC28 in the first and third parts 230 and 250 and twenty-eight layers of weft yarns Cn to CT28 at least in the first part 230. With the exception of the warp yarns located on the surface of the fibrous structure and some warp yarns present in the independent plies 2520, 2521, 2522 and 2523, each warp yarn 203 is periodically deflected from its path above a weft layer to, alternately, grasp a weft yarn of that weft layer and grasp together a weft yarn of that weft layer and the weft yarn located in the same column of the adjacent lower weft layer.This results in the formation of classic simple satin stitches PS 1 alternately with double satin stitches PS2 linking the threads of 2 adjacent weft layers, thus ensuring a link between weft layers.
[0051] On [Fig. 5]:
[0052] - twenty-eight layers of CTi to CT28 weft yarns forming the first part 230 are linked together by twenty-eight warp threads 203 layers of warp threads Cci to C C28,
[0053] - ten layers of CTi9 to CT28 weft yarns forming the basic portion 251 are linked between them by ten warp threads, 203 layers of warp threads CCi9 to CC28,
[0054] - four layers of CTi4 to CTi7 weft yarns forming the 2520 ply are bonded together by five CCi4 to CCi8 chain wires
[0055] - four layers of CT9 to CTi2 weft yarns forming the 2521 ply are bonded together by five warp threads Cc9 to CCb,
[0056] - three layers of CT5 to CT7 weft yarns forming the 2522 ply are bonded together by four warp threads CC5 to CC8,
[0057] - three layers of weft yarns Cn to CT3 forming the 2523 ply are linked together by four warp threads CCi to Cc4.
[0058] The fact that warp yarns CCi9 to CC28 do not extend into weft yarn layers CTi4 to CTi7 and that warp yarns CCi4 to CCi8 do not extend into weft yarn layers CTi9 to CTi28 ensures the unbinding 261 that separates the base portion 251 from the ply 2520. The fact that warp yarns CCi4 to CCi8 do not extend into weft yarn layers CT9 to CTi2 and that warp yarns Cc9 to CCb do not extend into weft yarn layers CTi4 to CTi7 ensures the unbinding 280 that separates the ply 2520 from the ply 2521. The fact that warp yarns Cc9 to CCb do not extend into the weft yarn layers The fact that the warp yarns CC5 to CCs do not extend into the weft yarn layers CT9 to CT12 ensures the unbinding 281 that separates the ply 2521 from the ply 2522. The fact that the warp yarns CC5 to CCs do not extend into the weft yarn layers Cn to CT3 and that the warp yarns CC1 to CC4 do not extend into the weft yarn layers CT5 to CT7 ensures the unbinding 282 that separates the ply 2522 from the ply 2523.
[0059] In the example described here, the weft yarns of the weft yarn layers CT4, CT8, CTi3 and CTi8 are not woven into the third part 250 of the fibrous structure 200 at the respective unlinkages 261, 280, 281 and 282. The unlinkages can also be made without removing weft yarns, i.e. by having the same number of weft yarns between the portions 230 and 250.
[0060] The armor plan shown in [Fig.5] is repeated on several successive armor plans in the transverse direction DT by shifting the single satin stitches PSI and the double satin stitches PS2 along the longitudinal direction DL from one armor plan to the next.
[0061] A similar multi-satin weave is used to realize the base portion 241 and the independent folds 2420, 2421, 2422 and 2423 of the deployment portion 242 of the second part 240 of the fibrous structure.
[0062] The same weaving logic can be applied with interlock, multi-weave and multi-twill weaves to achieve the fibrous structure 200. According to an embodiment variant, warp yarns present in the first part 230 can be deflected upwards and downwards along the thickness direction EP in order to cross at the bottoms of the unbundles, which makes it possible to reinforce said bottoms of unbundles.
[0063] Furthermore, the independent folds of each deployment portion can be woven according to a 3D or multilayer weave different from the 3D or multilayer weave weave of the rest of the fibrous structure.
[0064] At the end of the weaving, the fibrous structure 200 illustrated in [Fig.4] is obtained.
[0065] Figure 6 shows a preform 300 obtained by shaping the structure fibrous 200, that is to say, after folding, on the one hand, independent folds 2420, 2421, 2422 and 2423 of the deployment portion 242 at 90° with respect to the base portion 241 of the second part 240 and, on the other hand, independent folds 2520, 2521, 2522 and 2523 of the deployment portion 252 at 90° with respect to the base portion 251 of the third part 250.
[0066] Thanks to the presence of a plurality of loose folds in each deployment portion, the DS242 and DS232 overlap directions of the frame wires in the frame columns of deployment portions 242 and 252 respectively exhibit a much smaller angular variation than that obtained with monoblock deployment portions, i.e., not divided into a plurality of loose folds as shown in Figures 1 and 2. The frame columns in deployment portions 242 and 252 exhibit a shear angle α of less than 45° due to lower shear stresses during the folding of the unfolding portions. The detachment of the fibrous structure at the internal radii R1242 and R1252 and the external radii RE242 and RE252 is thus significantly reduced, allowing for better filling of the connecting radii by the fibrous texture.
[0067] The misalignment of the weft wire columns in the deployment portions is further reduced, thus improving the infiltration of the preform and better controlling the mechanical properties defined initially.
[0068] The example just described concerns a fibrous structure with several deployment portions woven simultaneously with base portions, with a debonding between the deployment and base portions. The invention is, of course, applicable to fibrous structures having different architectures, particularly simpler ones. The weaving process of the invention can be applied to weaving a fibrous structure comprising, along a longitudinal direction, a base portion extended by a deployment portion intended to be folded during the shaping of the fibrous structure in order to form an L-shaped preform, for example, in the case of manufacturing a stiffener from composite material.
[0069] The fibrous preform 300 is then densified to form a part made of composite material, in the example described here, a gas turbine ring sector. The densification of the fibrous preform intended to form the fibrous reinforcement of the part to be manufactured consists of filling the porosity of the preform, throughout all or part of its volume, with the material constituting the matrix. This densification can be carried out in a manner known per se, using the liquid process (CVL), the gas process (CVI), the ceramic filler injection process (Slurry Cast), the silicon alloy impregnation process (MI or RMI), or a combination of one or more of these processes.
[0070] The liquid process consists of impregnating the preform with a liquid composition containing a precursor of the matrix material. The precursor is usually in the form of a polymer, such as a high-performance epoxy resin, possibly diluted in a solvent. The preform is placed in a mold that can be sealed tightly with a cavity shaped like the final molded blade. The mold is then closed, and the liquid matrix precursor (for example, a resin) is injected into the entire cavity to impregnate all the fibrous material of the preform.
[0071] The transformation of the precursor into a matrix, namely its polymerization, is carried out by heat treatment, generally by heating the mold, after removal of any solvent and crosslinking of the polymer, the preform always being held in the mold having a shape corresponding to that of the part to be produced.
[0072] In the case of forming a carbon or ceramic matrix, the heat treatment consists of pyrolyzing the precursor to transform the matrix into a carbon or ceramic matrix, depending on the precursor used and the pyrolysis conditions. For example, liquid ceramic precursors, particularly SiC or SiCN, can be polycarbosilane (PCS), polytitanocarbosilane (PTCS), or polysilazane (PSZ) type resins, while liquid carbon precursors can be resins with a relatively high coke content, such as phenolic resins. Several consecutive cycles, from impregnation to heat treatment, can be carried out to achieve the desired degree of densification.
[0073] In particular, for the formation of an organic matrix, the densification of the fibrous preform can be achieved by the well-known resin transfer molding (RTM) process. According to the RTM process, the fibrous preform is placed in a mold having the external shape of the part to be produced. A thermosetting resin is injected into the internal space of the mold containing the fibrous preform. A pressure gradient is generally established in this internal space between the point where the resin is injected and the resin discharge ports in order to control and optimize the impregnation of the preform by the resin.
[0074] The densification of the preform can also be achieved by polymer impregnation and pyrolysis (PIP), or by impregnation with a slurry (“slurry cast”), containing for example SiC and organic binders, followed by infiltration with liquid silicon (“melt infiltration”).
[0075] The densification of the fibrous preform can also be achieved, in a known manner, by gaseous means through chemical vapor infiltration of the matrix (CVI). The fibrous preform corresponding to the fibrous reinforcement of the part to be produced is placed in a furnace into which a reactive gaseous phase is admitted. The pressure and temperature prevailing in the furnace and the composition of the gaseous phase are chosen so as to allow the diffusion of the gaseous phase within the porosity of the preform to form the matrix by deposition, at the core of the material in contact with the fibers, of a solid material resulting from the decomposition of a constituent of the gaseous phase or from a reaction between several constituents, unlike the pressure and temperature conditions specific to CVD (Chemical Vapor Deposition) processes which lead exclusively to deposition on the surface of the material.
[0076] The formation of a SiC matrix can be obtained with methyltrichlorosilane (MTS) giving SiC by decomposition of MTS while a carbon matrix can be obtained with hydrocarbon gases such as methane and / or propane giving carbon by cracking.
[0077] A densification combining liquid and gaseous routes can also be used to facilitate implementation, limit costs and manufacturing cycles while obtaining satisfactory characteristics for the intended use.
[0078] The densification processes described above make it possible to produce, from the fibrous structure of the invention, primarily parts made of organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC). Organic matrix composite (OMC), carbon matrix composite (C / C), and ceramic matrix composite (CMC) materials replace parts made of metallic materials in certain sections of turbomachinery. Their use contributes to optimizing aircraft performance, particularly by improving turbomachine efficiency and reducing the overall mass of the turbomachine, thereby significantly reducing harmful emissions (CO, CO2, NOx, etc.) and fuel consumption.
[0079] After densification, a part made of composite material is obtained.
[0080] The fibrous structure and its manufacturing process according to the present invention can in particular be used to produce turbine ring sectors, stiffeners, fixed or moving turbomachine blades.
Claims
Demands
1. A method for manufacturing a fibrous structure (200) by weaving between a plurality of layers of warp yarns (203) and a plurality of layers of weft yarns (204), the warp yarns extending along a longitudinal direction (DL), the weft yarns extending along a transverse direction (DT), the weft yarns (204) being woven in a plurality of columns spaced apart along the longitudinal direction, the weft yarns of each column of weft yarns being juxtaposed in the fibrous structure along a thickness direction (De) of said fibrous structure, the fibrous structure comprising a first part (230) in which all the layers of weft yarns (CTi-CT2s) are linked together by warp yarns of the plurality of warp layers (CCi-CC2s) by three-dimensional or multi-layer weaving and at least a second part (250) adjacent to the first part along the longitudinal direction (DL),the second part comprising a base portion (251) and a deployment portion (252) separated from each other by a first unlinking (261) extending along the longitudinal direction (DL) in the second part (250) of the fibrous structure (200) from a unlinking base (2610) adjacent to the first part (230) of the fibrous structure, characterized in that said deployment portion (252) of said at least a second part (250) of the fibrous structure is separated along the thickness direction (DE) into at least first and second plies (2520, 2521) unlinked by a second unlinking (280) extending along the longitudinal direction (DL) in the second part (250) of the fibrous structure from a unlinking base (2800) adjacent to the first part (230) of the fibrous structure, and in that the first and second plies (2520,2521) each comprise at least one layer of warp yarns from the plurality of layers of warp yarns of the first part of the fibrous structure and at least one layer of weft yarns, the warp yarns of said at least one layer of warp yarns being woven with the weft yarns of said at least one layer of weft yarns.
2. A method according to claim 1, wherein the first and second plies (2520, 2521) each comprise at least three layers of warp yarns from the plurality of warp yarn layers of the first part of the fibrous structure and at least three layers of weft yarns, said at least first and second plies being woven by three-dimensional or multi-layer weaving of the warp yarns of said at least three layers of warp yarns with the weft yarns of said at least three layers of weft yarns.
3. A method according to claim 2, wherein said at least first and second plies (2520, 2521) each comprise at most four layers of warp yarns from the plurality of warp yarn layers of the first part of the fibrous structure and four layers of weft yarns.
4. A method according to claim 2 or 3, wherein said at least first and second plies (2520, 2521) are each woven according to one of the following multilayer weaves: interlock, multi-satin, multi-twill and multi-plain.
5. A method for manufacturing a part made of composite material comprising: - weaving a fibrous structure (200) according to the weaving method according to any one of claims 1 to 4, - shaping the fibrous structure by folding said at least one unfolded portion (252) so as to obtain a fibrous preform (300), - densifying the fibrous preform (300) by a matrix.
6. Use of the manufacturing process for a part made of composite material according to claim 5 for the manufacture of a turbine ring sector, a stiffener or a fixed or moving turbomachine blade.
7. Fibrous structure (200) comprising a plurality of warp yarn layers (203) and a plurality of weft yarn layers (204), the warp yarns extending along a longitudinal direction (DL), the weft yarns extending along a transverse direction (DT), the fibrous structure comprising a plurality of weft yarn columns spaced apart along the longitudinal direction, the weft yarns of each weft yarn column being juxtaposed in the fibrous structure along a thickness direction (DE) of said fibrous structure, the fibrous structure comprising a first part (230) in which all the weft yarn layers (CTi-CT2s) are linked together by warp yarns of the plurality of warp layers (C ci-CC2s) by three-dimensional or multilayer weaving and at least a second part (250) adjacent to the first part along the longitudinal direction (DL),the second part comprising a base portion (251) and a deployment portion (252) separated from each other by a, first unbinding (261) extending along the longitudinal direction (DL) in the second part (250) of the fibrous structure (200) from a unbinding base (2610) adjacent to the first part (230) of the fibrous structure, characterized in that said unfolding portion (252) of said at least a second part (250) of the fibrous structure is separated along the thickness direction (DE) into at least first and second plies (2520, 2521) unbound by a second unbinding (280) extending along the longitudinal direction (DL) in the second part (250) of the fibrous structure from a unbinding base (2800) adjacent to the first part (230) of the fibrous structure, and in that the first and second plies (2520, 2521) each comprise at least one warp yarn layer from the plurality of warp yarn layers of the first part of the fibrous structure and at least one layer of weft yarns,the warp yarns of said at least one layer of warp yarns being woven with the weft yarns of said at least one layer of weft yarns.
8. Structure according to claim 7, wherein the first and second plies (2520, 2521) each comprise at least three layers of warp yarns from the plurality of layers of warp yarns from the first part of the fibrous structure and at least three layers of weft yarns, said at least first and second plies being woven by three-dimensional or multilayer weaving of the warp yarns of said at least three layers of warp yarns with the weft yarns of said at least three layers of weft yarns.
9. Structure according to claim 8, wherein said at least first and second plies (2520, 2521) each comprise at most four layers of warp yarns from the plurality of layers of warp yarns of the first part of the fibrous structure and four layers of weft yarns.
10. Structure according to claim 8 or 9, wherein said at least first and second plies (2520, 2521) are each woven according to one of the following multilayer weaves: interlock, multi-satin, multi-twill and multi-plain.
11. A composite material part comprising a fibrous reinforcement densified by a matrix characterized in that the fibrous reinforcement comprises a fibrous structure according to any one of claims 8 to 10.
12. Part according to claim 11, the part corresponding to a sector turbine ring, stiffener or fixed or moving turbomachine blade.