Method for three-dimensional or multi-layer weaving of fiber structures and fiber structures with three-dimensional or multi-layer weaving

Abstract

A fiber-reinforced fiber structure (400) intended to form a part made of a composite material comprises a fiber reinforcement densified by a matrix, the fiber structure having a three-dimensional or multi-layer weaving between a plurality of warp (201) layers and a plurality of weft (202) layers. The fiber structure comprises at least a first portion (411) and a second portion (412), the first portion having a first weaving type, the second portion continuing from the first portion and having a second weaving type, the degree of interlacing exhibited by the warp and weft in the first weaving type being greater than the degree of interlacing exhibited by the warp and weft from the second weaving type.

Description

Technical Field

[0001] This invention relates to the production of parts made of composite materials, and more particularly to the production of fiber-reinforced structures for such parts by three-dimensional (3D) or multi-layer weaving. Background Technology

[0002] The application field of this invention is the production of components made of structural composite materials; in other words, the production of structural components with fiber reinforcement and matrix densification. Composite materials make it possible to produce components with a lower overall mass than identical components (when they are made of metallic materials).

[0003] 3D or multi-layered weaving of fiber-reinforced fiber structures intended to form components made of composite materials, such as aircraft engine blades, is performed, for example, on a jacquard loom. The weaving involves inserting weft yarns between warp yarns to create a pattern. The warp yarns are organized into multiple layers and columns on the loom's heddles, which are manipulated by the loom to allow the insertion of weft yarns according to one or more weaving patterns programmed on the loom. The weft yarns are inserted column by column between the warp yarns. Document US2005 / 084377 describes the production of fiber preforms intended for manufacturing turbine blades made of composite materials through three-dimensional weaving.

[0004] In order to introduce each weft yarn during the weaving of the fiber structure, a system for drawing the warp yarns is associated with the loom. Placed downstream of the loom, this system serves to hold all the warp yarns together in a fixing or clamping device, and allows the warp yarns to travel a predetermined distance after the insertion of each weft yarn.

[0005] Therefore, a fixing device for the warp yarns upstream of the loom is necessary at the start of a new weaving of the fiber structure. At the end of the weaving, the fiber structure is released from the fixing device.

[0006] After weaving, the fiber structure has a loose, cohesive portion corresponding to the part of the fiber structure that was first woven and positioned closest to the fastener. In this portion, the first weft yarn column comes into contact with the area consisting solely of warp yarns without interlacing. Therefore, the density of the fabric produced downstream tends to push these first columns toward the fastener system, and the lack of interlacing facilitates this slippage.

[0007] Therefore, the fiber structure has a portion extending over a non-negligible length that cannot be retained to form the fiber reinforcement of the component to be manufactured, because the spacing between the weft rows is uncontrolled. In fact, the volumetric proportion of fibers in a component made of composite materials is a crucial parameter for the component's mechanical properties, and this proportion is determined by the type of weave and the control of the spacing between the yarn rows. This lack of control at the start of weaving leads to significant material loss, which increases the weaving time and manufacturing cost of the fiber structure.

[0008] Therefore, it is desirable to have a usable 3D or multilayer fiber structure without the aforementioned drawbacks. Summary of the Invention

[0009] Therefore, according to the first objective, the present invention proposes a method for weaving a fiber structure intended to form a fiber reinforcement of a component made of a composite material, the component comprising a matrix-densified fiber reinforcement, wherein the fiber structure is woven into a single piece through three-dimensional or multi-layer weaving between multiple warp layers and multiple weft layers, characterized in that the method comprises at least one first weaving step, wherein warp and weft yarns are woven according to a first weaving type, and a second weaving step, wherein warp and weft yarns are woven according to a second weaving type, wherein the degree of interlacing of the warp and weft yarns in the first weaving type is greater than the degree of interlacing of the warp and weft yarns present in the second weaving type.

[0010] The first section thus constitutes a starting block or "rear stop," which, due to its high degree of interlacing, prevents slippage of the weft yarns subsequently woven in the second section. Therefore, the space between the weft yarn rows is controlled from the start of weaving in the second section, allowing for the immediate attainment of a fiber structure that conforms to the defined weave type, and thus enabling significantly lower material loss than existing weaving techniques.

[0011] According to a specific aspect of the method of the invention, the degree of interlacing of the warp and weft yarns present in the first weave type is greater than or equal to 1.5 times the degree of interlacing of the warp and weft yarns present in the second weave type.

[0012] According to another aspect of the method of the present invention, the first and second weaves are of the same type.

[0013] In another specific aspect of the method according to the invention, the first and second weavings are of different types.

[0014] According to another specific aspect of the method of the invention, the first and second weaving types are selected from one of the following types: interlocking, 3D orthogonal, multi-layer plain weave or multi-layer twill weave or multi-layer satin weave.

[0015] According to another specific aspect of the method of the invention, the first type of weaving extends over at least four weft yarn columns in a continuous column of weft yarns.

[0016] Another object of the present invention is a method for manufacturing a component made of a composite material, the method comprising the following steps:

[0017] - Producing fiber structures conforming to the method of weaving fiber structures according to the present invention.

[0018] -Remove the first part of the fiber structure.

[0019] - To form a fiber preform into a fibrous structure to create the component to be manufactured.

[0020] - Dense fiber preforms.

[0021] Another object of the present invention is a fiber structure intended to form a fiber reinforcement for a component made of a composite material, the fiber structure comprising a matrix-densified fiber reinforcement having a three-dimensional or multi-layer weave between a plurality of warp layers and a plurality of weft layers, characterized in that the fiber structure comprises at least one first portion and a second portion, the first portion having a first weave type, the second portion continuing from the first portion and having a second weave type, wherein the degree of interlacing of the warp and weft yarns in the first weave type is greater than the degree of interlacing of the warp and weft yarns present in the second weave type.

[0022] According to a specific aspect of the fiber structure of the invention, the degree of interlacing of the warp and weft yarns present in the first weave type is greater than or equal to 1.5 times the degree of interlacing of the warp and weft yarns present in the second weave type.

[0023] According to another specific aspect of the fiber structure of the invention, the first fabric and the second fabric are of the same type.

[0024] According to another specific aspect of the fiber structure of the invention, the first fabric and the second fabric are of different types.

[0025] According to another specific aspect of the fiber structure of the invention, the types of the first weave and the second weave are selected from one of the following types: interlocking, 3D orthogonal, multi-layer plain weave, multi-layer twill weave, and multi-layer satin weave.

[0026] According to another specific aspect of the fiber structure of the invention, the first weave type extends over at least four weft yarn columns in a continuous column of weft yarns. Attached Figure Description

[0027] Figure 1 This is a schematic perspective view of a loom used to implement the weaving method of the present invention.

[0028] Figure 2 This is a cross-sectional view of the fiber structure in the warp direction according to an embodiment of the present invention.

[0029] Figure 3 yes Figure 2 A magnified partial cross-sectional view of a portion of the fiber structure in the warp direction.

[0030] Figure 4 yes Figure 2A magnified partial cross-sectional view of another part of the fiber structure in the warp direction, where the degree of interlacing is greater than that of the rest of the fiber structure. Detailed Implementation

[0031] This invention is generally applied to all fiber structures capable of forming fiber reinforcement through three-dimensional or multi-layer weaving, or to preforms for manufacturing components made of composite materials (particularly aircraft engine blades), wherein the fiber structure is densified by a matrix to obtain the component. This matrix is ​​typically resin in the case of composite materials used at relatively low temperatures (typically up to 300°C), or refractory materials such as carbon or ceramics in the case of thermostructural composite materials.

[0032] Here, the term “three-dimensional weaving” or “3D weaving” should refer to a weaving method in which at least some warp yarns are combined with weft yarns on multiple layers of weft yarns.

[0033] Here, the term "multi-layered weave" should refer to 3D weave with multiple weft layers, where the base weave of each layer is equivalent to conventional 2D fabric weave, such as plain weave, satin weave, or twill weave, but with certain points of weave that combine the weft layers together.

[0034] Producing fiber structures through 3D or multi-layer weaving allows for bonding between layers in a single textile operation, resulting in the good mechanical strength of the obtained fiber structure and parts made of composite materials.

[0035] Figure 1 The loom 100 shown is equipped with a jacquard mechanism 101, which consists of... Figure 1 The upper structure support is not shown. The loom 100 also includes a heald 110 consisting of a base plate 111 and control lines or healds 113, one end of each heald 113 being connected to a control hook 1010 of the jacquard mechanism 101, and the other end being connected to one of a return spring 102 fixed to the frame 103 of the loom 100. Each heald 113 includes an eyelet 114 through which warp yarns 201 pass. The healds 113 and their associated eyelets 114 extend in the region of the healds 113 and eyelets 114 driven by a substantially vertical oscillating motion indicated by double arrow F. The healds 113 are subjected to traction forces applied respectively by the control hook 1010 and the return spring 102. The healds 113 allow certain warp yarns 201 to be lifted according to a defined weaving program. By lifting certain warp yarns 201, the healds 113 thus create a shed, which allows the introduction of weft yarns 202 for 3D or multi-layer weaving of the fiber structure. Warp 201 consists of multiple warp layers C1 to C n organize.

[0036] Warp yarn 201 originates from a bobbin holder located upstream of the jacquard mechanism 101 on the loom 100. Figure 1 The spool (not shown in the image) is pulled. For this purpose, as... Figure 1 As shown, downstream of the loom 100, a system 300 for pulling the warp yarns is associated with the loom 100. A frame 120 defines the exit of the loom 100, in other words, the area after the warp yarns 201 are no longer woven with the weft yarns 202. The system 300 for pulling the warp yarns includes a set of warp layers C1 to C2 designed to be held downstream of the loom 100 by clamping. n Fixture 340.

[0037] During the weaving of the fiber structure 400, the fixing device is used in the forward direction D. A The upper drive warp 201. More specifically, in the embodiment described herein, the fixing device 340 is mounted on tracks 351 and 352 on the frame 350 of the system 300 for pulling the warp yarns, so as to enable the fixing device to move. The movement of the fixing device 300 is generated by an electric motor, such as a stepper motor (in... Figure 1 (Not shown in the image). Each time, when the weft yarn 202 rows intersect with the warp yarn layers C1 to C... n When fully knitted, the fixing device 340 is in direction D A The upper drive is a distance that allows the next weft yarn to be inserted into the loom 100 and woven in the loom.

[0038] Figure 2 A fiber structure 400 woven in a single piece using three-dimensional weaving is shown. Figure 2 The components of the fiber structure 400 shown correspond to the blade root preform 410, which is extended by the turbine blade fiber reinforced blade strut preform 420 made of composite material, followed by the airfoil or profile preform 430.

[0039] In the embodiments described herein, the fiber structure 400 is woven according to 3D “interlocking” weaving. Here, the term “interlocking” weaving refers to a weaving in which each layer of weft yarns connects multiple layers of warp yarns, wherein all yarns in the same weft row have the same movement in the weaving plane. Specifically, detailed exemplary embodiments for forming fiber-reinforced fiber preforms for aircraft engine blades from 3D-woven fiber blanks are described in detail in documents US 7 101 154, US 7 241 112, and WO 2010 / 061140.

[0040] The blade root preform 410 corresponds to the first braided portion of the blade preform (i.e., the first braided portion that leaves the loom), and then, in the extension of the blade root preform 410, the braided strut preform 420 and the aerodynamic airfoil or profile blade preform portion 430 are braided.

[0041] According to the present invention, the fiber structure 400 has a first portion 411 at the beginning of the preform 410 at the root of the blade, and the weave type of the first portion 411 has a greater degree of interlacing of the warp and weft yarns than the direction D corresponding to the forward direction of the fiber structure at the loom exit. A The degree of interlacing of warp and weft yarns is exhibited by the weaving type in the second weaving section 412, which is located downstream of the first weaving section.

[0042] The degree of interlacing between warp and weft yarns in a three-dimensional fabric can be calculated using the following formula:

[0043] T E =N CT / (R A ×E T ×E C )

[0044] in:

[0045] -T E Corresponding to the degree of interlacing between warp and weft yarns in a three-dimensional fabric,

[0046] -N CT The number of layers corresponding to the intersection of warp and / or weft yarns.

[0047] -R A This corresponds to the weave ratio, or in other words, the number of weft yarn rows that repeat on a pattern corresponding to a certain weave type.

[0048] -E T Corresponding to the spacing between two weft columns, this spacing can also be defined as the weft texture ( Figure 3 and Figure 4 ),

[0049] -E C Corresponding to the spacing between warp rows, this spacing can also be defined as the warp texture (such as in...). Figure 3 and Figure 4 For E T (As shown).

[0050] Figure 3 This is an enlarged partial view of the weft cross-section of the second weave portion 412, obtained by 3D weaving between warp yarns 201 and weft yarns 202 according to interlocking weaving. In this embodiment, the number N of the weft yarn layers where the warp yarns intersect is... CT It is 2, the weaving ratio R A It is 10 (weft rows), and the spacing E between two weft rows is... T It is 2mm, and the spacing E between the two warp rows C(Not shown in 3) is 3mm. Therefore, the degree of interlacing T here is... E yes:

[0051] T E =2 / (10×2×3)=0.033.

[0052] Figure 4 This is an enlarged partial view of the weft cross-section of the first woven portion 411, obtained through 3D weaving between warp yarns 201 and weft yarns 202. In this embodiment, the number N of the weft yarn layers where the warp yarns intersect is... CT It is 3, the weaving ratio R A It is 8 (weft rows), and the spacing E between two weft rows is... T It is 2mm, and the spacing E between the two warp rows C (exist Figure 4 (Not shown in the image) is 3mm. Therefore, the degree of interlacing T here is... E yes:

[0053] T E =3 / (8×2×3)=0.0625.

[0054] Therefore, the first part 411 has a greater degree of interlacing than the part 412 corresponding to the rest of the fiber structure.

[0055] The first section 411 thus constitutes a starting block or "rear stop block," which, due to its high degree of interlacing, prevents slippage of the weft yarns subsequently woven in the second section 412. Therefore, from the beginning of weaving in the second section 412, the space between the weft yarn rows (weft weave) is controlled, which allows for the immediate attainment of a fiber structure that conforms to the defined weave type, and thus enables significantly lower material loss than existing weaving techniques.

[0056] In the fiber structure of the present invention, the only sacrificial component, in other words, the component of the fiber structure that is removed from the fiber reinforcement constituting the component made of the composite material to be produced, is the first part with a high degree of interlacing.

[0057] The weaving type used in the first and second parts of the fiber structure can be the same, such as Figure 3 and 4 The diagram shows an interlocking weave type, but with different degrees of interlacing between the two sections. Alternatively, the weave type used in the first section can be different from the weave used in the second section, for example, if the weave used in the second section cannot be repeated with a higher degree of interlacing in the first section.

[0058] As a non-limiting embodiment, the weave type used to form the first part and / or the second part may be selected from one of the following types: interlocking, 3D orthogonal, multi-layer plain weave, multi-layer twill weave, multi-layer satin weave.

[0059] Furthermore, the various parts of the fiber structure according to the invention are each combined with different types of weaves. In practice, for example, it may be advantageous to promote a surface state without significant irregularities after densification, in other words, a good finishing state, so as to avoid or limit finishing operations by machining or to avoid the formation of resin clumps in the case of resin matrix composites. For this purpose, in the case of fiber structures having an inner part or core and an outer part or outer surface, it is preferable to produce the surface with plain weave, satin weave, or twill weave types to limit the irregularities of these surfaces; the satin weave type additionally provides a smooth surface appearance.

[0060] It is desirable to use yarns with different chemical properties between different components of the fiber structure, especially between the core and the outer layer, in order to impart specific properties to the resulting components made of composite materials, particularly in terms of abrasion resistance and oxidation resistance.

[0061] Therefore, in the case of components made of thermostructural composites reinforced with refractory fibers, a fiber structure having carbon fibers in the core and ceramic fibers (e.g., silicon carbide (SiC)) on the surface can be used to increase the wear resistance and oxidation resistance of the composite component at that part of the surface.

[0062] According to a specific feature of the invention, the portion of the woven fiber structure extends over at least four consecutive weft yarn rows (in the forward direction of the fiber structure at the loom exit) with an interlacing degree greater than that of one or more portions of the fiber texture woven upstream of the first woven section.

[0063] According to another specific feature of the invention, the degree of interlacing of the warp and weft yarns in the first weaving type is greater than or equal to 1.5 times the degree of interlacing of the warp and weft yarns in the second weaving type.

[0064] Once the fiber structure is woven, the first portion 411, with a high degree of interlacing, is removed. According to an alternative embodiment, the first portion 411 may be removed at a later stage in the manufacture of the component made of the composite material, for example, after densification by machining. The fiber structure is shaped by compression to form a ready-to-use, densified fiber preform. The fiber preform is then densified to form a component made of the composite material, such as a blade. Densification of the fiber-reinforced fiber preform intended to form the component to be manufactured involves filling all or part of the volume of the preform's pores with the material constituting the matrix. This densification can be carried out in a manner known per se, following a liquid method (CVL) or a gas method (CVI), or a method of injecting ceramic filler (slurry casting), or a method of impregnation with silicon alloy (MI or RMI), or in a sequence of one or more of these methods.

[0065] The liquid method involves impregnating a preform with a liquid composition comprising a precursor containing a matrix material. The precursor is typically in the form of a polymer, such as a high-performance epoxy resin, optionally diluted in a solvent. The preform is placed in a mold that can be closed in a sealing manner, having recesses in the shape of the molded final blade. The mold is then closed, and a matrix precursor liquid (e.g., resin) is injected into all the recesses to impregnate all fibrous components of the preform.

[0066] The conversion of the precursor to the matrix (i.e., its polymerization) is carried out by heat treatment (usually by heating the mold) after any solvents and polymer crosslinking are removed, and the preform is always held in a mold with a shape corresponding to the shape of the part to be produced.

[0067] In the case of forming a carbon ceramic matrix, the heat treatment includes pyrolysis of precursors to convert the matrix into a carbon or ceramic matrix, depending on the precursors used and the pyrolysis conditions. For example, the ceramic liquid precursor, particularly SiC or SiCN, can be a polycarbosilane (PCS), polytitanium carbosilane (PTCS), or polysilazane (PSZ) resin, while the carbon liquid precursor can be a resin with a relatively high coke content, such as a phenolic resin. Several consecutive cycles can be performed from impregnation to heat treatment to achieve the desired degree of densification.

[0068] Especially in the case of forming an organic matrix, the densification of fiber preforms can be achieved through the well-known method of resin transfer molding (RTM). According to the RTM method, the fiber 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 fiber preform. Typically, a pressure gradient is established in this internal space between the resin injection point and the orifice for resin removal to control and optimize the impregnation of the preform with the resin.

[0069] Densification of preforms can also be achieved by polymer impregnation and pyrolysis (PIP) or by slurry impregnation (“slurry casting”), in which the polymer contains, for example, SiC and an organic binder, followed by infiltration with liquid silicon (“melt infiltration”).

[0070] Densification of fiber preforms can also be achieved in a known manner via a gaseous process, specifically through chemical vapor infiltration (CVI). A fiber-reinforced preform corresponding to the blade to be produced is placed in a furnace, and a reactive gaseous phase is introduced. The dominant pressure and temperature in the furnace, as well as the composition of the gaseous phase, are selected so that the phase can diffuse within the pores of the preform, allowing the deposition of solid material at the core of the material in contact with the fibers, where a matrix forms. This deposition is produced by the decomposition of the gaseous phase components or by the reaction between several components, in contrast to the pressure and temperature conditions specific to CVD methods (“chemical vapor deposition”) that specifically result in deposition at the material surface.

[0071] SiC matrix can be formed by using methyltrichlorosilane (MTS) to produce SiC through the decomposition of MTS, while carbon matrix can be obtained by using hydrocarbon gases, such as methane and / or propane, to provide carbon through cracking.

[0072] Densification methods that combine liquid and gaseous approaches can also be used to facilitate implementation, limit costs and manufacturing cycles, while achieving satisfactory properties for the intended application.

[0073] The densification method described above enables the production of most parts from the fiber structure of the present invention, made of composite materials having an organic matrix (CMO), a carbon matrix (C / C), and a ceramic matrix (CMC).

[0074] In the production of parts made of oxide / oxide composites, the fiber structure is impregnated with a slurry containing refractory oxide particles. After removing the liquid phase of the slurry, the resulting preform is heat-treated to sinter the particles and obtain a refractory oxide matrix. The impregnation of the structure can be performed using methods that exhibit a pressure gradient, such as injection molding-type methods "RTM" or submicron powder suction methods, known as "APS".

[0075] After densification, a component made of composite material is obtained.

[0076] In particular, the fiber structure and manufacturing method according to the present invention can be used to produce turbine blades, such as turbine rotor blades, fan blades, propellers, landing gear components, blade fan sections for gas turbine nozzles, and flow rectifiers.

Claims

1. A method for manufacturing a component made of a composite material, the method comprising the following steps: - A method for producing a fiber structure; the fiber structure is intended to form a fiber reinforcement for a turbine blade made of a composite material, the fiber structure comprising a matrix-densified fiber reinforcement, the fiber structure being woven into a single piece on a loom through three-dimensional or multi-layer weaving between multiple warp layers and multiple weft layers, the fiber structure comprising a blade root preform, characterized in that the method comprises at least one first weaving step, wherein warp and weft yarns are woven according to a first weaving type to form a first portion of the blade root preform of the fiber structure, and a second weaving step, wherein warp and weft yarns are woven according to a second weaving type to form a second portion of the blade root preform of the fiber structure, the second portion continuing from the first portion and located downstream of the first portion in the direction of advance of the fiber structure at the loom exit, the degree of interlacing of the warp and weft yarns in the first weaving type being greater than the degree of interlacing of the warp and weft yarns present in the second weaving type, the degree of interlacing corresponding to the ratio of the number of layers of interlaced warp or weft yarns divided by the weaving ratio, the product of the spacing between two weft rows and the spacing between two warp rows; - Remove the first part of the fiber structure. - To form a fiber preform into a fibrous structure to create the component to be manufactured. - Dense fiber preforms.

2. The method according to claim 1, wherein, The degree of interlacing between the warp and weft yarns in the first weaving type is greater than or equal to 1.5 times the degree of interlacing between the warp and weft yarns in the second weaving type.

3. The method according to claim 1, wherein, The first and second weaves are of the same type.

4. The method according to claim 1, wherein, The first and second weaves are of different types.

5. The method according to claim 3, wherein, The first and second weave types are selected from one of the following: interlocking, 3D orthogonal, multi-layer plain weave, multi-layer twill weave, or multi-layer satin weave.

6. The method according to claim 1, wherein, The first weave type extends on at least four rows of continuous weft yarns.

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