Method for manufacturing a part of revolution from composite material with the insertion of an inter-ply anti-stick coating
The interposition of a non-stick material strip between fibrous texture turns in the manufacturing process addresses deformation and stress issues in composite turbine blower housings, enhancing stress distribution and mechanical properties without increasing mass.
Patent Information
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- SAFRAN AIRCRAFT ENGINES SAS
- Filing Date
- 2024-05-13
- Publication Date
- 2026-06-05
AI Technical Summary
Existing composite material gas turbine blower housings suffer from deformation and stress concentration on the outer face due to penetrating or non-penetrating impacts, leading to increased mass and size when metal strips are used for reinforcement, and lack of resistance in non-impacted zones.
A method involving the interposition of a non-stick material strip between fibrous texture turns during the manufacturing process to create a delamination zone, distributing stress and maintaining structural integrity without increasing overall mass.
The method reduces deformation on the external face while preserving structural integrity and mechanical properties, achieving improved stress distribution and energy dissipation in composite material parts.
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Abstract
Description
Title of the invention: Method for manufacturing a part of revolution made of composite material with the insertion of an inter-ply anti-adhesive layer technical field
[0001] The present invention relates to the general field of manufacturing parts of revolution exposed to impacts and more particularly, but not exclusively, to gas turbine blower housings for aircraft engines. Prior art
[0002] In a gas turbine aircraft engine, the fan casing performs several functions. It defines the air intake duct into the engine, supports an abradable material opposite the fan blade tips, supports an optional sound-wave absorption structure for acoustic treatment at the engine inlet, and incorporates a retention shield. The retention shield acts as a debris trap, retaining debris, such as ingested objects or fragments of damaged blades, ejected by centrifugal force, to prevent them from passing through the casing and reaching other parts of the aircraft.
[0003] Previously made of metallic material, housings, such as the blower housing, are now made of composite material, that is to say from a fibrous preform densified by an organic matrix, which makes it possible to produce parts with a lower overall mass than the same parts when made of metallic material while having at least equivalent or even greater mechanical resistance.
[0004] The manufacture of a blower housing from an organic matrix composite material is described in particular in US patent 8,322,971. In the housing disclosed in US patent 8,322,971, the retention shield is formed by an excess thickness obtained in the housing's fibrous reinforcement, which has a progressively increasing thickness. The fibrous reinforcement is obtained by winding a 3D woven fibrous texture, which has an excess thickness suitable for forming a retention shield. The housing thus obtained exhibits good mechanical properties at the retention shield, both in terms of puncture resistance (retention) and dynamic behavior.
[0005] However, since the structural zones outside the retention zone are thinner, they offer less resistance to penetrating or non-penetrating impacts. Consequently, deformation of the outer face of the housing may occur when it is subjected to penetrating or non-penetrating forces.
[0006] Prior art solutions exist that aim to improve the resistance to deformation of the outer face of the housing. In this regard, document FR3109180 describes a housing with a metal strip on its outer surface. However, this solution results in a significant increase in the overall size and mass of the housing, particularly for a blower housing with a large diameter.
[0007] Furthermore, prior art solutions have the disadvantage of concentrating stresses on the outer face of the housing when it is subjected to penetrating or non-penetrating impacts. Indeed, the structure of prior art housings consists of a single piece or several layers bonded together. Thus, when the housing is subjected to a penetrating or non-penetrating impact, maximum stress or deformation is generated on the face opposite the force, namely the outer face of the housing. Description of the invention
[0008] The main purpose of the present invention is therefore to propose a solution for the manufacture of a blower housing which does not have the aforementioned disadvantages.
[0009] To this end, the invention proposes a method for manufacturing a part of revolution made of composite material for a gas turbine, comprising the following steps:
[0010] - the winding of a fibrous texture onto several superimposed turns on a mandrel in order to obtain a fibrous preform of a shape of revolution corresponding to that of the part of revolution to be manufactured, said preform extending in width along an axial direction, in thickness along a radial direction and in length along a circumferential direction,
[0011] - the densification of the fibrous preform by a matrix,
[0012] characterized in that, during the winding of the fibrous texture onto the mandrel, the the method further comprises an interposition of at least one strip of non-stick material between at least two adjacent turns of the fibrous texture, said at least one strip of non-stick material extending in the circumferential direction along the interface between said at least two adjacent turns and in that said at least one strip of non-stick material has a width less than the width of the preform in the axial direction.
[0013] Thus, the manufacturing process makes it possible to obtain a part of revolution with a delamination zone, which promotes the distribution of stresses within the fibrous reinforcement. This reduces the deformation generated on the external face of the part while maintaining its overall structural integrity.
[0014] When the part is subjected to an impact, each of its layers will deform in isolation and dissipate part of the energy received before transmitting it to the adjacent layer.
[0015] Furthermore, the process makes it possible to obtain a part made of composite material having improved mechanical properties without increasing the overall mass.
[0016] The term “delamination” refers to a phenomenon which includes the at least partial dissociation of several layers in the fibrous reinforcement of the part.
[0017] According to a particular feature of the process of the invention, said at least one strip of non-stick material can extend over a width of between 5% and 25% of the width of said preform.
[0018] Such a width allows for a better compromise between good stress distribution and good overall structural integrity of the part.
[0019] This range of values makes it possible to obtain a good ratio between the reduction of the deformation on the external face of said part and the preservation of its structural integrity.
[0020] According to a particular feature of the process of the invention, the non-stick material can be chosen from polytetrafluoroethylene, paints, ceramics, alloys or a mixture thereof.
[0021] According to a particular feature of the process of the invention, the non-stick material may comprise polytetrafluoroethylene. Polytetrafluoroethylene has the advantage of very good chemical inertness, which prevents it from bonding to the matrix during densification and facilitates delamination. It also has the advantage of being flexible, which allows it to optimally conform to the surface of the fibrous texture on which it is placed.
[0022] The invention also relates to a part of revolution made of composite material for a gas turbine, comprising fibrous reinforcement densified by a matrix, the fibrous reinforcement comprising a fibrous texture having a three-dimensional weave in the form of a band, said fibrous texture being wound on itself in several turns, said part extending in width along an axial direction, in thickness along a radial direction between a first and a second opposite face, and in length along a circumferential direction, characterized in that said reinforcement comprises a band of non-stick material between at least two adjacent turns of said fibrous texture,said at least one strip of non-stick material extending circumferentially along the interface between said at least two adjacent turns, and said at least one strip of non-stick material has a width less than the width of said reinforcement in the axial direction.
[0023] Thus, it is possible to distribute the stresses within the fibrous reinforcement when the part is subjected to penetrating or non-penetrating impacts. It is also possible to reduce the deformation generated on the external face of the part while maintaining its structural integrity. Furthermore, the composite material part according to the invention has the advantage of improved mechanical properties without increasing the overall mass.
[0024] According to a particular feature of the part of the invention, said at least one strip can extend over a width between 10% and 25% of the width of said reinforcement.
[0025] According to a particular feature of the part of the invention, the non-stick material can be chosen from polytetrafluoroethylene, paints, ceramics, alloys or a mixture thereof. Brief description of the drawings
[0026] Other features and advantages of the present invention will become apparent from the description given below, with reference to the attached drawings which illustrate examples of embodiment without any limiting character.
[0027] [Fig.1] Figure [Fig.1] schematically represents a turbomachine housing in one embodiment of the invention,
[0028] [Fig.2] Fig.2 is a cross-sectional view along plane ILII of the housing of Fig.1, showing the stacking of the superimposed towers of the housing according to an embodiment in the delamination zone of the housing,
[0029] [Fig.3] Fig.3 is a perspective view showing the shaping of a fibrous texture and a strip of non-stick material intended to form the reinforcement of the blower housing of Fig.1.
[0030] [Fig.4] Fig.4 is a schematic perspective view of a loom showing the weaving of a fibrous texture used for the formation of the fibrous reinforcement of the casing of Fig.1.
[0031] [Fig.5] The [Fig.5] is a schematic view showing the simultaneous winding of the fibrous structure and the strip into an anti-stick material of the [Fig.3],
[0032] [Fig.6] Fig.6 is a cross-sectional view showing the profile of the fibrous preform obtained after winding the fibrous structure and the strip with an anti-stick material of Figures 3 and 5,
[0033] [Fig. 7] Fig. 7 is a schematic view showing a tool for densifying the fibrous preform obtained after winding with a matrix. Description of embodiments
[0034] The invention applies generally to any gas turbine composite material part of revolution comprising a retention shield.
[0035] A manufacturing process for a part of revolution of the invention is described below, applied according to a first example, to a blower housing for an aeronautical gas turbine engine.
[0036] Such an engine, as shown very schematically by [Fig.1], comprises, from upstream to downstream in the direction of the gas flow, a blower 1 disposed at the inlet of the engine, a compressor 2, a combustion chamber 3, a high-pressure turbine 4 and a low-pressure turbine 5.
[0037] The motor is housed inside a casing comprising several parts corresponding to different elements of the motor. Thus, the blower 1 is surrounded by a blower casing 10 having a shape of revolution.
[0038] The fan housing 10 is here made of an organic matrix composite material, that is to say, from a fiber reinforcement, for example, of carbon, glass, aramid, or ceramic, densified by a polymer matrix, for example, epoxy, bismaleimide, or polyimide. The manufacture of such a housing is described in particular in US patent 8,322,971. The internal surface 11 of the housing defines the engine's air intake duct.
[0039] The housing 10 extends in width along an axial direction DA between its upstream and downstream ends (from left to right in [Fig. 2]), which are here provided with external flanges 14, 15 to allow its mounting and connection with other elements. The housing extends in thickness along a radial direction and in length along a circumferential direction. According to the invention, the housing 10 includes a delamination zone 12 ([Fig. 1]).
[0040] The fibrous reinforcement is formed by winding a fibrous texture 140 made by three-dimensional weaving onto a mandrel 200, the mandrel having a profile corresponding to that of the housing to be made ([Fig.3]).
[0041] The fibrous reinforcement of the housing 10 consists of a plurality of superimposed layers 141 to 144 of a fibrous texture 140 in the form of a strip having a three-dimensional or multi-layer weave, each layer 141 to 144 corresponding to a winding turn of the fibrous texture 140 ([Fig.2]).
[0042] In addition, a strip of non-stick material 150 is interposed between two adjacent layers of the fibrous texture, the strip of non-stick material 150 having a width li50 less than the width li40 of the fibrous texture 140 ([Fig.3]) and delimiting the delamination zone of the housing 10.
[0043] In the example described in [Fig. 2], the layers 151 to 153 of the non-stick material 150 are interposed between the superimposed layers 141 to 144 of the fibrous texture 140, each layer 151 to 153 corresponding to one winding of the non-stick material 150. Generally, the non-stick material 150, which forms a delamination portion, can be interposed between two or more layers of fibrous texture. 140 superimposed layers, each corresponding to one winding of said fibrous texture 140. In [Fig. 2], the thickness of layers 151 to 153 has been intentionally exaggerated to facilitate understanding of [Fig. 2]. The interposition of the strip of a non-stick material 150, between two or more layers of fibrous texture 140, does not necessarily generate an increase in thickness in the fibrous texture 140 or in the final part.
[0044] In prior art solutions, the structure of the part of revolution is either a single piece or composed of several layers of fibrous texture bonded to one another. Thus, when the housing is subjected to penetrating or non-penetrating forces, maximum stress and deformation are generated on the outer face opposite the force, i.e., the outer surface of the housing. By adding a strip made of a non-stick material, it is possible to give the part specific mechanical properties. Indeed, the interposition of the non-stick material strip generates a structure comprising several locally decoupled layers and, consequently, the presence of delamination within the structure of the part. Thus, when the part is subjected to penetrating or non-penetrating forces, each portion of the delaminated layer will deform and dissipate energy before transmitting the stress to the adjacent layer.The stress is therefore distributed within the layers of the casing. It is thus possible to reduce the deformation generated on the outer face while maintaining the overall structural integrity of the part.
[0045] Furthermore, the addition of the strip made of a non-stick material facilitates the delamination of adjacent axial portions. The width of the fibrous texture covered by the non-stick material strip constitutes a delamination initiation zone. Delamination propagates easily and rapidly from the initiation zone to the adjacent axial portions not covered by the non-stick material strip. Thus, a portion of the energy received during the impact is dissipated by each layer of the part.
[0046] The strip made of a non-stick material can extend over a width of between 5% and 25% of the width of said fibrous reinforcement
[0047] The strip made of a non-stick material can extend over a width that corresponds to 10% of the width of said fibrous reinforcement.
[0048] This allows us to obtain the best compromise between a good distribution of stresses and a good overall structural integrity of the part.
[0049] The non-stick material can be chosen from polytetrafluoroethylene, paints, ceramics, alloys.
[0050] The thickness of the strip in a non-stick material may be less than or equal to 0.9 mm (to be confirmed).
[0051] The non-stick material may include, in particular, polytetrafluoroethylene. Polytetrafluoroethylene has the advantage of having very good chemical inertness This allows it to avoid bonding to the matrix during densification and facilitates delamination. It also has the advantage of being flexible, enabling it to optimally conform to the surface of the fibrous texture on which it is placed.
[0052] A manufacturing process for the blower housing 10 is now described.
[0053] As illustrated in [Fig.4], a fibrous texture 140 is produced in a known manner by weaving using a jacquard type loom 100 on which a bundle of warp yarns or strands 20 has been arranged in a plurality of layers, the warp yarns being linked by weft yarns or strands 30. The fibrous texture 140 is produced by three-dimensional weaving.
[0054] 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.
[0055] The creation of the fibrous texture by 3D weaving makes it possible to obtain a bond between the layers, thus having good mechanical strength of the fibrous structure and of the part in composite material obtained, in a single textile operation.
[0056] As illustrated in [Fig. 4], the fibrous texture 140 has a band-like shape extending lengthwise in a direction X corresponding to the direction of the warp yarns or strands 20 and widthwise or transversely in a direction Y corresponding to the direction of the weft yarns or strands 30. As explained below, the fibrous reinforcement of the part of revolution, here the housing 10, is formed by the fibrous texture 140, which is shaped by winding it upon itself ([Fig. 3]). Consequently, in the fibrous reinforcement of the final part, the warp yarns or strands extend along the circumferential direction Dc ([Fig. 1]) while the weft yarns or strands extend along the axial direction DA ([Fig. 1]).
[0057] The fibrous texture 140 can in particular be woven from fiber yarns of carbon type, ceramic such as silicon carbide, glass, or aramid.
[0058] As illustrated in [Fig. 3], a fibrous preform is formed by winding the fibrous texture 140, produced by three-dimensional weaving, onto a mandrel 200. The mandrel has a profile corresponding to that of the housing to be produced. According to the invention, a strip of non-stick material 150 is wound simultaneously with the fibrous texture 140. The strip 150 is positioned above the first layer 141 of the texture 140 wound onto the mandrel 200 so as to interpose a layer of strip of non-stick material 150 of narrower width between two adjacent layers of greater width fibrous texture corresponding to two winding turns of fibrous texture 140. The strip 150 is positioned at a location on the fibrous texture 140 corresponding to the axial delamination zone to be formed in the part.
[0059] According to a particular feature of the invention, the width li40 can correspond to one winding turn of the fibrous texture 140.
[0060] The mandrel 200 has an external surface 201 whose profile corresponds to the internal surface of the housing to be produced. By winding onto the mandrel 200, the fibrous texture 140 conforms to its profile. The mandrel 200 also includes two flanges 220 and 230 to form portions of the fibrous preform corresponding to the flanges 14 and 15 of the housing 10 ([Fig. 3]).
[0061] During the formation of the fibrous preform by winding, the fibrous texture 140 and the strip in an anti-stick material 150 are called from drums 60 and 70 respectively on which they are stored as illustrated in [Fig.5].
[0062] Figure 6 shows a cross-sectional view of the fibrous preform 300 obtained after winding the fibrous texture 140 and the strip of non-stick material 150 in several layers on the mandrel 200. In the example described here, the preform 300 comprises 4 layers 141 to 144 of fibrous texture 140 and 3 layers 151 to 153 of strip 150 of non-stick material interposed respectively between the adjacent layers 141 and 142, 142 and 143, and 143 and 144. The thickness of the layers 151 to 153 in Figure 6 has been intentionally amplified to facilitate understanding of Figure 6. The interposition of the strip in a non-stick material 150, between two or more layers of fibrous texture 140, does not necessarily generate an overthickness in the fibrous texture 140 or in the final piece.
[0063] The preform 300 can comprise 4 layers 141 to 144 of fibrous texture 140 and a layer of strip in a non-stick material 150.
[0064] A fibrous preform 300 is obtained with a delamination zone formed by the interposition of the layers 151 to 153 of the strip 150 between the superimposed layers 141 to 144 of the fibrous texture 140.
[0065] The fibrous preform 300 is then densified by a matrix.
[0066] The densification of the fibrous preform consists of filling the porosity of the preforms, in all or part of its volume, by the material constituting the matrix.
[0067] The matrix can be obtained in a manner known per se following the liquid-based process.
[0068] The liquid process consists of impregnating the preform with a liquid composition containing an organic precursor of the matrix material. The organic precursor is usually in the form of a polymer, such as a resin, The fibrous preform is placed in a mold that can be sealed tightly with a cavity shaped like the final molded part. As illustrated in [Fig. 7], the fibrous preform 300 is positioned between a plurality of sectors 240 forming a counter-mold and the mandrel 200 forming a support, these elements having, respectively, the external and internal shapes of the housing to be produced. Next, the liquid matrix precursor, for example, a resin, is injected throughout the cavity to impregnate the entire fibrous portion of the preform.
[0069] The transformation of the precursor into an organic 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, which has a shape corresponding to that of the part to be produced. The organic matrix can be obtained, in particular, from epoxy resins, such as, for example, a commercially available high-performance epoxy resin, or from liquid precursors of carbon or ceramic matrices.
[0070] According to one aspect of the invention, 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 shape of the housing to be produced. A thermosetting resin is injected into the internal space defined between the mandrel 200 and the counter-molds 240, which includes 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.
[0071] The resin used can be, for example, an epoxy resin. Resins suitable for RTM processes are well known. They preferably have a low viscosity to facilitate their injection into the fibers. The choice of temperature class and / or the chemical nature of the resin is determined according to the thermomechanical stresses to which the part must be subjected. Once the resin has been injected throughout the reinforcement, it is polymerized by heat treatment in accordance with the RTM process.
[0072] After injection and polymerization, the part is demolded. Finally, the part is trimmed to remove excess resin and the chamfers are machined to obtain the housing 10 illustrated in [Fig.1].
Claims
Demands
1. A method for manufacturing a part of revolution (100) made of composite material for a gas turbine, comprising the following steps: - winding a fibrous texture (140) onto several superimposed turns (141, 142, 143, 144) on a mandrel (200) to obtain a fibrous preform (300) of a shape of revolution corresponding to that of the part of revolution to be manufactured, said preform extending in width along an axial direction (DA), in thickness along a radial direction (DR) and in length along a circumferential direction (Dc), - densifying the fibrous preform (300) with a matrix, characterized in that, during the winding of the fibrous texture (140) onto the mandrel (200) the method further comprises interposing at least one strip of a non-stick material (150) between at least two adjacent turns of the fibrous texture (140),said at least one strip of non-stick material (150) extending in the circumferential direction (Dc) along the interface between said at least two adjacent turns and in that said at least one strip of non-stick material has a width less (li50) than the width of the preform (lu0) in the axial direction (DA).
2. Method according to claim 1, wherein said at least one strip extends over a width between 5% and 25% of the width of said preform (300).
3. A method according to any one of claims 1 or 2, wherein the non-stick material is selected from polytetrafluoroethylene, paints, ceramics, alloys or a mixture thereof.
4. A composite material part of revolution for a gas turbine, comprising a matrix-densified fibrous reinforcement, the fibrous reinforcement comprising a fibrous texture having a three-dimensional, band-like weave, said fibrous texture (140) being wound upon itself in several turns, said part extending in width along an axial direction (DA), in thickness along a radial direction (DR) between a first and a second opposite face, and in length along a circumferential direction (Dc), characterized in that said reinforcement comprises a band of a non-stick material (150) between at least two adjacent turns of said fibrous texture, said at least one strip of non-stick material (150) extending in the circumferential direction (Dc) along the interface between said at least two adjacent turns and in that said at least one strip of non-stick material has a width less (150) than the width of said reinforcement (1¼ 0) in the axial direction (DA).
5. Part according to claim 4, wherein said at least one the band extends over a width between 5% and 25% of the width of said reinforcement.
6. Part according to any one of claims 4 or 5, in which The non-stick material is chosen from polytetrafluoroethylene, paints, ceramics, alloys or a mixture thereof.