Component with improved wear resistance

Abstract

The present application relates to a component (1) made of an organic matrix composite material, which has, on its surface (S), a wear-resistant area (20) comprising a resin (24) containing polytetrafluoroethylene particles (22).

Description

Technical Field

[0001] The present invention relates to a component made of an organic matrix composite material (“organic matrix composite”; “OMC”) and to the manufacture of such a component, the component having improved wear resistance. Background Art

[0002] Organic matrix composites are generally used under conditions where components are in frictional contact with each other. The friction coefficient of common matrices of structural composites with organic thermosetting or thermoplastic matrices is relatively high. The contact and friction encountered during operation generate significant heat and wear.

[0003] It is known to introduce carbon fillers into a polymer matrix, but even with this solution, the friction coefficient of the obtained components may still remain high. Therefore, the wear resistance provided by this solution can be further improved.

[0004] Therefore, there is a need for solutions that improve the wear resistance of components made of organic matrix composite materials while maintaining the relatively simple manufacture of these components and without causing an increase in their volume. Summary of the Invention

[0005] The present invention relates to a component made of an organic matrix composite material, which has a wear-resistant region on its surface that contains a resin containing polytetrafluoroethylene particles.

[0006] Compared with the introduction of carbon fillers proposed in the prior art, the wear-resistant region of the component of the present invention has a reduced coefficient of dynamic friction and provides a significant improvement in the wear resistance of the component. In addition, the solution of the present invention can maintain the relatively simple manufacture of the component and does not cause an increase in its volume, and the geometry and dimensions of the component are not significantly changed. In particular, the present invention makes it possible to dispense with the use of metal wear elements added and assembled by bonding to the component, which solution would lead to more complex manufacture and incompatible different expansions during operation.

[0007] In an exemplary embodiment, the mass content of the polytetrafluoroethylene particles in the wear-resistant region is 5% - 65%, for example 10% - 60%.

[0008] Such a content advantageously helps to further improve the wear resistance while avoiding any risk of changing the properties of the composite component.

[0009] In an exemplary embodiment, the median size of the polytetrafluoroethylene particles is 0.1 μm - 50 μm, or even 0.5 μm - 50 μm or 0.1 μm - 10 μm, or even 0.5 μm - 5 μm.

[0010] Unless otherwise specified, “median size” shall refer to the size of half of the population given by the statistical particle size distribution, called D50.

[0011] In an exemplary embodiment, the component is a turbine component, such as an aircraft turbine component. The component can be, for example, the movable cowl ("transcowl") of a thrust reverser or the cowl ("fancowl") of a fan.

[0012] The invention also relates to an assembly comprising the above-mentioned first component and a second component separate from the first component, which is in contact with the wear-resistant area of the first component.

[0013] In use, the first and second components are intended to be in frictional contact with each other on the wear-resistant area. According to one example, the second component can have the above structure, that is, it can be made of an organic matrix composite material and has a second wear-resistant area on its surface, which contains a second resin containing second polytetrafluoroethylene particles, and the wear-resistant area of the first component is in contact with the second wear-resistant area.

[0014] The invention also relates to a turbine comprising the above assembly.

[0015] The invention also relates to a method for manufacturing the above-mentioned component, which at least comprises:

[0016] - forming a layer containing a resin in a fluid state and polytetrafluoroethylene particles on the surface of a substrate made of an organic matrix composite material, and

[0017] - curing the resin in a fluid state on the substrate, thereby forming a wear-resistant area and obtaining a composite component.

[0018] It is also possible to perform a known surface treatment on the substrate before forming the layer containing the resin in a fluid state and polytetrafluoroethylene particles. According to one example, a fiber texture and an optional adhesive can be positioned on the substrate before forming the layer on top.

[0019] Alternatively, according to a first embodiment, the method is a method for manufacturing the above-mentioned component, which at least comprises:

[0020] - forming a layer containing a resin in a fluid state, which contains polytetrafluoroethylene particles, on the surface of a fiber structure pre-impregnated with a fluid matrix composition, and

[0021] - co-curing the resin in a fluid state with the fluid matrix composition, thereby forming a wear-resistant area and obtaining a composite component.

[0022] Alternatively, according to a second embodiment, the method is a method for manufacturing the above-mentioned component, which at least comprises:

[0023] - forming a layer containing a resin in a fluid state, which contains polytetrafluoroethylene particles, on the surface of a fiber structure,

[0024] - Introducing a fluid matrix composition into the pores of the fibrous structure, and

[0025] - Curing the resin in a fluid state together with the introduced fluid matrix composition to form a wear-resistant area and obtain a composite component.

[0026] In the case of the above two methods, co-curing can be achieved by co-crosslinking (co-crosslinking) of the resin and the matrix composition. This is the case when the resin and the matrix composition are thermosetting. Subsequently, co-curing can be carried out by co-solidification without crosslinking of the resin and the matrix composition. This is the case when the resin and the matrix composition are thermoplastic. Description of the Drawings

[0027] Figure 1 Schematically shows a cross-section of an exemplary component of the present invention.

[0028] Figure 2 Schematically shows a cross-section of an exemplary assembly of the present invention.

[0029] Figure 3 Shows the product obtained after the first step of the first exemplary manufacturing method of the component of the present invention.

[0030] Figure 4 Shows the product obtained after the second step of the first exemplary manufacturing method of the component of the present invention.

[0031] Figure 5 Shows the product obtained after the first step of the second exemplary manufacturing method of the component of the present invention.

[0032] Figure 6 Shows the product obtained after the second step of the second exemplary manufacturing method of the component of the present invention.

[0033] Figure 7 Shows the product obtained after the first step of the third exemplary manufacturing method of the component of the present invention.

[0034] Figure 8 Shows the product obtained after the second step of the third exemplary manufacturing method of the component of the present invention.

[0035] Figure 9 Shows the product obtained after the third step of the third exemplary manufacturing method of the component of the present invention.

[0036] Figure 10 Is the result of a comparative test, which shows the difference in the coefficient of kinetic friction between the component of the present invention and the component outside the present invention.

[0037] Figure 11For comparative test results, which show the difference in the coefficient of kinetic friction between the components of the present invention and components outside the present invention.

[0038] Figure 12 For comparative test results, which show the difference in the amount of wear after a friction test between the components of the present invention and components not of the present invention. Detailed implementation mode

[0039] Figure 1 Shows an example of component 1 of the present invention. Component 1 is made of an organic matrix composite material, which comprises a fiber reinforcement densified by an organic matrix. The organic matrix is present in the pores of the fiber reinforcement and covers and bonds the fibers of the reinforcement. The combination of the fiber reinforcement and the organic matrix forms the organic matrix composite material, which is represented by the symbol 10 in Figure 1-4 Shown.

[0040] The fiber reinforcement can have various structures. For example, the fiber reinforcement can be formed by a stack of fiber textures (such as a two-dimensional fabric or a unidirectional layer) or by a fabric obtained by three-dimensional weaving. The fibers forming the fiber reinforcement can be carbon fibers, fibers of ceramic materials different from carbon (such as silicon carbide or alumina), glass fibers or polymer fibers.

[0041] The organic matrix of component 1 can be a solid thermoplastic polymer or a polymeric and solid thermosetting polymer. For example, the organic matrix can be an epoxy resin matrix, a polyurethane matrix, a polyamide matrix, a polyetherimide matrix (PEI) or a polyetheretherketone matrix (PEEK).

[0042] Component 1 has a wear-resistant area 20 on its surface S, which comprises a resin 24 containing polytetrafluoroethylene particles 22. Generally speaking, for reasons of readability, the size of this area 20 in the figure is enlarged. Hereinafter, for reasons of simplicity, unless otherwise specifically mentioned, the term "polytetrafluoroethylene particles" is expressed as "PTFE particles" or "particles", and the term "wear-resistant area" is expressed as "area". The resin 24 constitutes a solid matrix, which contains the particles 22. The coefficient of kinetic friction of the area 20 can be less than or equal to 0.1, for example less than or equal to 0.06. The coefficient of kinetic friction can be measured by the method of alternating friction test with load.

[0043] The area 20 is a surface part of component 1, which is located between the outer surface S of component 1 and its fiber reinforcement. The area 20 can be in contact with the fibers of the fiber reinforcement of component 1. In particular, the particles 22 can be in contact with and / or inserted between the fibers of the fiber reinforcement. Alternatively, the area 20 can be separated from the fibers of the fiber reinforcement by the organic matrix of component 1.

[0044] The thickness e of the area 20 10It can be less than or equal to 0.5 mm, for example, 0.01 mm - 0.3 mm.

[0045] Region 20 defines the outer surface S of component 1 and is intended to come into contact with and rub against a second component separate from component 1 during use. Figure 2 This aspect is shown, where second component 2 is in contact with region 20 of component 1. Component 1 and second component 2 are intended to be in frictional contact during use (represented by arrow F). It should be noted that the frictional surface of second component 2 in contact with region 20 may or may not have the same type of wear-resistant region as region 20.

[0046] In Figure 1 the example of, PTFE particles 22 are selectively located in region 20, that is, only present on the surface of component 1 and not in the entire composite material 10 covered by region 20. However, if particles 22 are present both on the surface of component 1 and in the entire composite material 10 covered by region 20, it does not depart from the scope of the present invention. Thus, according to one example, PTFE particles can be incorporated into the organic matrix of component 1.

[0047] Resin 24 can be thermoplastic in the solid state or thermoplastic in the polymeric and solid states. Resin 24 can be an organic resin. Resin 24 can be the same as or different from the organic matrix. For example, resin 24 can be an epoxy resin, a polyurethane resin, a polyamide resin, a polyetherimide resin, or a polyetheretherketone resin.

[0048] The mass content of PTFE particles in region 20 can be greater than or equal to 5%, for example, greater than or equal to 10%. The mass content of PTFE particles in region 20 can be 5% - 65%, for example, 10% - 60%.

[0049] The median size of the PTFE particles can be greater than or equal to 0.1 μm, for example, greater than or equal to 0.5 μm. The median size of the PTFE particles can be less than or equal to 50 μm, for example, less than or equal to 10 μm, for example, less than or equal to 5 μm, for example, less than or equal to 2 μm. The median size of the PTFE particles can be 0.1 μm - 50 μm, for example, 1 μm - 50 μm or 0.1 μm - 10 μm, for example, 1 μm - 10 μm or 0.1 μm - 5 μm, for example, 1 μm - 5 μm or 0.1 μm - 2 μm, for example, 1 μm - 2 μm. The PTFE particles can be in the form of fine grains, fibrils, or fibril bundles. In the form of fibrils or bundles, the maximum length can reach 0.05 mm.

[0050] For example, available PTFE particles can include PTFE particles with a reference number of 430935 - 100g sold by Sigma - Aldrich (median particle size of 1 micron).

[0051] The mass content of the resin in region 20 can be greater than or equal to 35%, for example greater than or equal to 40%. The mass content of the resin in region 20 can be 35% - 95%, for example 35% - 90% or 40% - 95%, for example 40% - 90%.

[0052] After an example of the structure of the component of the present invention has been described, reference is now made to Figure 3-9 Describe several manufacturing methods.

[0053] Figure 3 and 4 shows the product obtained in the two-step process of the first exemplary manufacturing method of the present invention. In this example, region 20 is formed on a substrate 10 made of an organic matrix composite material, the manufacture of which has been completed previously. The organic matrix of the substrate 10 has been cured previously. In the case of a thermosetting matrix, the organic matrix of the substrate 10 is in a polymerized state. For example, this variant can be implemented in the case of repairing the substrate 10 that wears against the second component 2 during use or in the case of manufacturing a component to be used for the first time (a component in a new state).

[0054] First, form Figure 3 the product shown, which has a substrate 10 made of an organic matrix composite material and a layer containing a fluid resin 23 containing PTFE particles 22, and this layer is present on the surface S1 of the substrate 10. This layer can be in contact with the surface S1 of the substrate 10. This layer contains the fluid resin 23 and the particles 22 and can be formed in different ways.

[0055] According to one example, the resin 23 can be directly deposited in a fluid state on the surface S1, with or without the particles 22. Thus, the fluid resin 23 containing the particles 22 in the mixture can be directly deposited on the surface S1 of the substrate 10, or the fluid resin 23 can be deposited on the substrate 10 first and then the particles 22 can be deposited, or the particles 22 can be deposited first and then the fluid resin 23 can be deposited.

[0056] According to an alternative, the resin can be deposited on the surface S1 in a solid form, for example in the form of a film containing the particles 22) or in the form of a powder mixture containing resin particles and the particles 22. In the case where the resin is deposited on the surface S1 in a solid state, the step of fluidizing the resin deposited on the substrate 10 (for example by heating) is carried out to obtain Figure 3The product shown. Before forming the layer containing the fluid resin 23 and the particles 22, the surface of the substrate 10 can be preliminarily treated, for example, by sanding and / or sandblasting (plasma, corona, laser, etc.). This preliminary surface treatment can cause some fibers of the fiber reinforcement of the substrate 10 to be exposed on the surface, such that the fluid resin 23 and the particles 22 are then in contact with these exposed fibers.

[0057] In a second step, the curing of the fluid resin 23 is carried out. This curing can be effected by cooling Figure 3 the product, so that it can be frozen when the resin is a thermoplastic resin, or by polymerization of the resin 23 when a thermosetting resin is involved. This polymerization can be activated by heating. After this curing, the region 20 is formed and the Figure 4 composite part shown is obtained. The adhesion of the region 20 to the underlying substrate 10 can be carried out by adhesive bonding pre-deposited on the surface of the substrate 10 and / or by the fluid resin 23 penetrating into the surface pores of the substrate to form a plurality of anchor points. This adhesion can also be carried out by locally melting the underlying substrate followed by cooling, so that the substrate 10 and the region 20 can be co-frozen, especially in the case of a thermoplastic organic matrix.

[0058] It should also be noted that, in order to obtain the desired dimensions of the region 20 and the part 1 to be obtained, the step of compacting the fluid resin 23 can be carried out before the end of its curing. As shown, this compaction step makes it possible to go from a layer of fluid resin 23 having a thickness e1 as shown to a region 20 having a thickness e Figure 3 (which is less than e1, for example less than or equal to 90% of e1), as 10 shown. Figure 4 shown.

[0059] The case just described Figure 3 and 4 relates to the manufacture of a part by forming a region 20 on a substrate made of an organic matrix composite, the manufacture of the substrate having been pre-completed. The case where the resin and the particles are deposited before the manufacture of the organic matrix composite will now be described in conjunction with Figure 5-9 this.

[0060] Therefore, Figure 5 and 6Shows a second exemplary method for manufacturing the components of the present invention. This example involves first forming a layer comprising a fluid resin 23 containing particles 22 on the surface S2 of a fibrous structure pre-impregnated with a fluid matrix composition 40. The fibrous structure is intended to form the fiber reinforcement of the composite component to be obtained. The matrix composition 40 is intended to form the organic matrix of the composite component to be obtained. In the example shown, the fibrous structure is formed by a stack of fibrous layers 30 impregnated with the matrix composition 40, which can be a thermoplastic or thermosetting organic polymer. Alternatively, a fibrous structure formed by three-dimensional weaving can be used.

[0061] In a manner similar to that associated with Figure 3 and Figure 4 shown, the resin 23 and the particles 22 can be deposited directly, as a mixture or separately, and in a fluid or solid state.

[0062] After that, the Figure 5 product can be heat-treated to copolymerize the matrix composition 40 and the resin 23 (in the case of two thermosetting polymers) to obtain a component comprising an organic matrix composite 110 having, on its surface S, a region 20 ( Figure 6 ). According to an alternative, in the case of a thermoplastic polymer, cooling can be carried out to co-cure the resin 23 and the matrix composition 40 and obtain a composite component.

[0063] As described above, compaction can be carried out before the end of co-curing, thereby reducing the thickness of the region 20 to a thickness e less than the thickness e1 of the layer comprising the fluid resin 23 10 . Compaction can obtain an organic matrix composite 110 having a thickness e 20 which is less than the thickness e2 of the fibrous structure impregnated with the matrix composition 40, for example less than or equal to 90% of e2.

[0064] However, the present invention is not limited to forming a fluid resin layer on a structure pre-impregnated with a matrix composition. In fact, Figure 7-9 an alternative manufacturing process starts with forming a layer comprising a fluid resin 23 and particles 22 on the surface S3 of a dry fibrous structure (not pre-impregnated). After forming this layer, the fluid matrix composition 40 is introduced into the fibrous structure. It should be noted that compaction can be carried out before or after introducing the matrix composition 40. The introduction of the matrix composition 40 can be carried out by injection or infusion. After that, co-curing of the matrix composition 40 and the resin 23 is carried out by copolymerization or co-cooling as described above.

[0065] The features described above in connection with Figure 1 the components apply to the components obtained in the various manufacturing examples described.

[0066] Now in connection withFigure 10-12 Describe the performance of the components of the present invention. These figures provide the results of comparative tests between the components of the present invention and components outside the present invention. The components evaluated are components made of an organic matrix composite material, which has a resin containing different types of particles in an amount greater than 20% by mass (30 - 60% in the surface resin layer) on its surface. The median size of the particles contained is about 1 μm. In these figures, "R" represents a carbon / epoxy resin composite having no particles on its surface, while "1" represents the results of the components of the present invention having PTFE particles on its surface. The symbols "2" to "5" are composites having various PTFE particles on their surfaces.

[0067] Figure 10 Show the experimental results, which show the change of dynamic friction over time during the test. The tests conducted include alternating motion under a constant compressive force.

[0068] It can be seen that during the friction test, the components of the present invention containing PTFE particles show a much lower coefficient of dynamic friction than the other composite material components tested. Figure 11 Show that the components of the present invention have an average coefficient of dynamic friction close to 0.05 in the test, which is much lower than the average coefficient of dynamic friction of the other components evaluated, which is greater than 0.3. Figure 12 Show the results of the surface wear of the evaluated products in frictional contact obtained at the end of the test. It can be seen that after correcting for the volume of compressive deformation during the test, the components of the present invention are the components with the minimum amount of wear.

[0069] The expression "between... and..." should be understood to include the boundaries.

Claims

1. A method for manufacturing a component, the component comprising a first part and a second part separate from the first part, the first and second parts being intended to be in frictional contact, the first part being made of an organic matrix composite material which has, on its surface, a wear-resistant area comprising a resin containing polytetrafluoroethylene particles, the polytetrafluoroethylene particles being present only on the surface of the first part, the second part being made of an organic matrix composite material which is in contact with the wear-resistant area of the first part, the resin and the matrix composition being linked by co-crosslinking, wherein the resin and the matrix composition are thermosetting, the method comprising at least: - forming, on the surface of a fibrous structure pre-impregnated with a fluid matrix composition, a layer comprising a resin in a fluid state which contains polytetrafluoroethylene particles, and - co-curing the resin in a fluid state and the fluid matrix composition, thereby forming the wear-resistant area and obtaining the first part made of a composite material, and - bringing the wear-resistant area of the first part thus obtained into contact with the second part, The co-curing step is carried out by co-crosslinking of the resin and the matrix composition.

2. A method for manufacturing a component, the component comprising a first part and a second part separate from the first part, the first and second parts being intended to be in frictional contact, the first part being made of an organic matrix composite material which has, on its surface, a wear-resistant area comprising a resin containing polytetrafluoroethylene particles, the polytetrafluoroethylene particles being present only on the surface of the first part, the second part being made of an organic matrix composite material which is in contact with the wear-resistant area of the first part, the resin and the matrix composition being linked by co-crosslinking, wherein the resin and the matrix composition are thermosetting, the method comprising at least: - forming, on the surface of a fibrous structure, a layer comprising a resin in a fluid state which contains polytetrafluoroethylene particles, - introducing a fluid matrix composition into the pores of the fibrous structure, - co-curing the resin in a fluid state and the introduced fluid matrix composition, thereby forming the wear-resistant area and obtaining the first part made of a composite material, and - bringing the wear-resistant area of the first part thus obtained into contact with the second part, The co-curing step is carried out by co-crosslinking of the resin and the matrix composition.

3. The method according to claim 1 or 2, wherein The mass content of polytetrafluoroethylene particles in the wear-resistant area of the first part is 5%-65%.

4. The method according to claim 3, wherein, The mass content of polytetrafluoroethylene particles in the wear-resistant area of the first part is 10%-60%.

5. The method according to claim 1 or 2, wherein The median size of the polytetrafluoroethylene particles of the first part is 0.1 μm-50 μm.

6. The method according to claim 5, wherein The median size of the polytetrafluoroethylene particles of the first part is 0.5 μm-50 μm.

7. The method according to claim 1 or 2, wherein The first part (1) is a turbine part.

8. The method according to claim 1 or 2, wherein The second part has, on its surface, a second wear-resistant area which comprises a second resin containing second polytetrafluoroethylene particles, the wear-resistant area of the first part being in contact with the second wear-resistant area.

9. A turbine comprising a component manufactured by the method according to claim 1 or 2.

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