Method for treating a turbomachine part made of composite material

Abstract

The present invention relates to a method for treating a part made of composite material, in particular for an aircraft turbomachine or for an aircraft, the part comprising at least one layer covering a surface of this part, this method comprising a step (a) of pickling at least one layer of the part so as to at least partly prepare the layer, wherein, before the pickling step (b), the method comprises a step (a) of scarifying the at least one layer of the part, and wherein the at least one layer is an anti-erosion layer.

Description

[0001]DESCRIPTION TITLE: METHOD FOR TREATMENT OF A TURBOMACHINE PART MADE OF COMPOSITE MATERIAL Technical Field of the Invention The present invention relates to the field of treatments for a part made of composite material, particularly for an aircraft turbomachine. In particular, the present invention relates to a method for treating a part made of composite material. Technical Background The prior art includes, in particular, documents FR-A1-3138624, US-A1-2022 / 403747, US-A1-2018 / 250762 and US-A1-2009 / 272245. Generally speaking, every part is designed to meet specific functions and environmental constraints. This is especially true for both metallic and composite materials. To meet these environmental constraints, surface treatments that offer protective properties are commonly used.particularly through the application of one or more protective layers. These protective layers are generally very sensitive to external aggressions and require touch-ups or repairs. Furthermore, composite parts can be formed from different materials and often in a non-homogeneous manner (for example: a carbon fiber composite part with a polymer matrix and a metallic part) in order to meet functional specifications. Surface treatments may be identical or different depending on the base material of the part. In the industrial sector, it is therefore common practice to treat metallic or composite parts to prepare their external surface for cleaning, repair, and / or touch-ups. In the aeronautical sector, particularly for aircraft turbomachinery,More and more parts are being made of composite materials to achieve a lower overall mass than the same parts made of metal, while offering at least equivalent, if not superior, mechanical strength. A composite part is generally repaired or reworked by manually performing a stripping step, such as sanding or polishing. This can be a lengthy and tedious process. Indeed, manual stripping can require physical effort from the operator and may cause musculoskeletal disorders (MSDs). Furthermore, stripping can present a risk of damaging parts of the piece that should be retained (for example, when cleaning to remove contamination with an abrasive medium) and / or a risk of damaging a surface beneath the layer being removed, or even surrounding components. In addition,Material removal by manual stripping may not be uniform over a given surface, and thus may result in inaccuracies regarding the thickness removed. The composite part may be subjected to a surface preparation operation (particularly before the application of an additional coating), which is traditionally performed by sandblasting. Sandblasting can have the disadvantage of contaminating the surface of the part with blasting media and may also require an additional cleaning step to remove the blasting media. Therefore, there is a need to provide an effective treatment for parts made of composite materials, especially for aircraft turbomachinery, that allows for the stripping of at least one layer of the part without damaging or altering its properties. Summary of the invention: The invention aims to provide a simple, effective, and economical solution to at least one of the aforementioned drawbacks. To this end,The invention relates to a method for treating a part made of composite material, particularly for an aircraft turbomachine or for an aircraft, the part comprising at least one layer covering a surface of that part. This method includes a step (b) of stripping at least one layer of the part so as to prepare at least part of said at least one layer. According to the invention, before the stripping step (b), the method includes a step (a) of scarifying at least one layer of the part, so as to initiate the stripping by creating incisions in the layer. According to the invention, at least one layer of the part is an anti-erosion layer. Thus, this solution makes it possible to achieve the aforementioned objective. In general, the method according to the invention makes it possible to obtain at least one stripped layer (or in other words, a stripped external surface of the part) without damaging the part made of composite material. Indeed,The process according to the invention makes it possible to prepare (for example, by removal and / or cleaning) the necessary quantity (such as a layer thickness) of material to be removed from the layer to be treated in a homogeneous manner, particularly before implementing reconstruction solutions (such as touch-ups, repairs, application of additional coatings, etc.). In particular, scarification upstream of the layer to be stripped makes it possible to create controlled incisions (or notches, or in other words, cracks) in this layer to initiate the stripping process. This facilitates crack propagation and enhances material removal at the level of the layer to be treated without altering the other components and / or properties of the part. Furthermore, scarification also enhances the removal of contaminants that may be particularly resistant to stripping. For example,The composite part may include an anti-erosion layer that offers good resistance to the initiation of damage. Thus, the incisions made by scarification in this anti-erosion layer facilitate the propagation of cracks and their removal during pickling. Furthermore, the scarification and pickling steps can be adapted for automated processing (for example, by a suitable machine). Finally, the process according to the invention is less harmful to the health of operators than manual and / or chemical pickling, less energy-intensive, and does not pollute the part. The term "pickling" or "pickled" refers to the removal (or machining), which may be partial or total, of a layer (or, in other words, a surface, particularly an external one) of the composite part. The term "scarification" or "scarified" refers to an operation that initiates the pickling process by preparing the layer to be treated.for example by creating incisions in the layer to be treated (or a part of the layer to be treated or removed). The treatment process according to the invention may include one or more of the following features, taken individually or in combination with each other: - the anti-erosion layer is a multilayer comprising, for example, a first underlayer (called, for example, the bonding layer) and a second underlayer (called, for example, the anti-erosion layer), the second underlayer extending above or below the first underlayer; - the first underlayer is made of epoxy and the second underlayer is made of polyurethane; - the scarification step (a) is carried out on the entirety of at least one layer of the part; - the scarification and stripping steps (a, b) are carried out by projecting a jet of water at, respectively, a first predetermined pressure and a second pressure; - the steps (a,b) Scarification and pickling are carried out by projecting a water jet at, respectively, a first parameter and a second parameter; - the first pressure is higher than the second pressure; - the first pressure is between 1500 and 2000 bar, and the second pressure is between 1000 and 2000 bar; - the water jet is demineralized and without abrasives; - the water jet is projected by a single nozzle, a multi-nozzle, or a nozzle with several sapphires; - before and / or after the pickling step (b), the process further includes a step (i) of inspecting at least one layer of the part; - a measuring device, for example a camera or a sensor, is connected to the nozzle or multi-nozzle so as to check at least one layer of the part; - the turbomachine or aircraft part is a blade, for example, of a fan,or a housing; -- step (b) of stripping at least one layer of the part so as to remove at least part of said at least one layer; -- step (b) of stripping at least one layer of the part so as to clean at least part of said at least one layer; -- a predetermined thickness is scarified during the scarification step; -- the predetermined thickness is 2.00 mm; -- the composite material comprises an organic or ceramic matrix; -- the part comprises fibers embedded in a resin; -- the fibers are woven, preferably in three dimensions; -- the fibers are glass fibers, carbon fibers, aramid fibers, polyamide fibers, ceramic fibers, metallic fibers, or a mixture of at least two of these fibers; -- the resin is a thermoset, for example selected from polyurethane, epoxy, polybismaleimide, polyimides, or phthalonitrile, or the resin is a thermoplastic,for example, chosen from polyetheretherketone, polyaryletherketone, or polyetherimide; - the pickling step is followed by a deposition step, for example, of an additional coating or a protective shield on the pickled surface; -- the part is multi-component and / or multi-material; -- the blade comprises a blade having an intrados face and an extrados face extending transversely between a leading edge and a trailing edge of this blade, in which a protective shield is placed on the pickled surface in the deposition step, for example, by bonding; -- the part made of composite material is a blade of an aircraft compressor or turbomachine. The invention may relate to the use of a treatment process according to one of the features of the invention, for preparing one or more surfaces of the part made of composite material.for example, of a turbomachine blade before application (e.g., by bonding) or reconstruction of a coating or protective shield (such as a metallic shim). The invention may also relate to the use of a treatment process according to one of the features of the invention for repairing one or more damaged areas of a part made of composite material, for example, a turbomachine blade. The invention may also relate to the use of a treatment process according to one of the features of the invention for retouching one or more areas of a part made of composite material. The invention may further relate to the use of a treatment process according to one of the features of the invention for cleaning at least one component of the part.such as a metallic protective shield for a turbomachine blade or a polyurethane film for a turbomachine blade. Brief description of the figures. Other features and advantages of the invention will become apparent upon reading the detailed description that follows, for the understanding of which reference should be made to the accompanying drawings in which: Figure 1 is a half-view schematically representing an axial cross-section of an aircraft turbomachine; Figure 2 is a schematic perspective view of a blade for a fan of the turbomachine of Figure 1; Figure 3 is a block diagram of the steps in a process for treating a part made of composite material.such as the blade in Figure 2; Figure 4 schematically represents a treatment of the part in composite material; Figure 5 schematically and partially represents an axial cross-sectional view of an example of the blade in Figure 2; Figure 6 schematically and partially represents an axial cross-sectional view of another example of the blade in Figure 2. Elements having the same functions in the different implementations have the same reference numerals in the figures. Detailed description of the invention By convention, in the description below, the terms "longitudinal" and "axial" refer to the orientation of structural elements extending along the direction of a longitudinal axis (such as the longitudinal axis of a turbomachine). The terms "radial" or "vertical" refer to the orientation of structural elements extending in a direction perpendicular to the longitudinal axis. The terms "inner" and "outer,"and "internal" and "external" are used with reference to positioning relative to the longitudinal axis. Thus, a structural element extending along the longitudinal axis has an inner face facing the longitudinal axis and an outer surface opposite its inner surface. The invention relates to a treatment of a part 10 made of composite material, in particular for an aircraft turbomachine 1 or for an aircraft. The part 10 can be multi-component and / or multi-material. By way of example, the part 10 can be a 2, 2a, 2b made of composite material of the turbomachine 1 which includes a protective shield 3 made of metallic material on its leading edge. In the following description, the invention will be described in the context of its application to a blade 2, 2a, 2b made of composite material,particularly for a fan 1a of the turbomachine 1. Figure 1 illustrates a non-limiting example of a ducted turbomachine 1. The turbomachine 1 may be a turbojet or turboprop. The turbomachine 1 extends around a longitudinal axis X. It may include, from upstream to downstream in the direction of gas flow F along the longitudinal axis X, the fan 1a, at least one compressor (such as a low-pressure compressor 1b and a high-pressure compressor 1c), a combustion chamber 1d, at least one turbine 1e (such as a high-pressure turbine and a low-pressure turbine), and a nozzle (not shown). The turbomachine 1 may also include a rectifier 1f that rectifies the flow at the outlet of an upstream rotor in order to provide maximum thrust at the outlet of the turbomachine 1. In the particular example of Figure 1,The rectifier 1f is located downstream of the fan 1a and rectifies a secondary flow F2. The fan 1a draws in an airflow that splits into a primary flow F1 and a secondary flow F2. The primary flow F1 passes through a primary channel of the turbomachine 1, while the secondary flow F2 is directed to a secondary channel surrounding the primary channel. The primary flow F1 is compressed within the low-pressure compressor 1b and then the high-pressure compressor 1c. The compressed air is then mixed with fuel and burned in the combustion chamber 1d. The gases formed by combustion pass through the high-pressure turbine and the low-pressure turbine. The gases finally escape through the nozzle, whose cross-section allows for the acceleration of these gases to generate thrust. The secondary flow F2 passes through the rectifier 1f, which accelerates the circulation of the secondary flow F2 to generate propulsion. The fan 1a,The low-pressure compressor 1b, the high-pressure compressor 1c, the high-pressure and / or low-pressure turbine 1e, and the rectifier 1f each include blades 2. The blades 2 can be movable (for example, blade 2a in Figure 2), rotating about the X-axis, or fixed (blade 2b, called the OGV for "Outlet Guide Vane," of rectifier 1f in Figure 1) relative to the X-axis. Blades 2, 2a, and 2b can be made of composite material. In particular, blade 2a can include fibers embedded in a resin. The resin can thus form a matrix for densifying the composite material. The composite material can be an organic or ceramic matrix. In other words, the resin can be organic or ceramic. The resin can be a thermoset or a thermoplastic. For example, thermosetting resin can be chosen from polyurethane, epoxy, polybismaleiimide (BMI),polyimides or phthalonitrile. The thermoplastic resin can be chosen from polyetheretherketone (PEEK), polyaryletherketone (PAEK), or polyetherimide (PEI). The fibers can be glass fibers, carbon fibers, aramid fibers, polyamide fibers, ceramic-type fibers (e.g., silicon carbide SiC), or metallic fibers (e.g., titanium Ti). The fibers can be a mixture of at least two of the aforementioned fibers (e.g., silicon carbide titanium SiC-Ti). The fibers can be woven, preferably in three dimensions. The fibers can also be woven in two dimensions to form one or more fabrics that can be used by draping to make the blade. Alternatively, the fibers can be laminated. By definition,A laminated fiber is formed by stacking several layers bonded to one another. The laminated fibers are configured to form a web of nonwoven fibers. Blade 2, 2a, 2b may include carbon fibers embedded in epoxy. With reference to Figure 2, blade 2a may extend, on the one hand, along a longitudinal axis A (horizontal in Figure 2), and on the other hand, along an elongation axis B (vertical in Figure 2). This axis A is substantially perpendicular to axis B. Axis A is substantially parallel to the X-axis of the turbomachine 1. The blade 2a may comprise a blade 20 having an intrados face 21 and an extrados face 22 extending transversely between a leading edge 23 and a trailing edge 24. The blade 20 may have an aerodynamic profile to form the aerodynamic part of the blade 2a. For this purpose,The blade 20 may have a curved profile of varying thickness between its leading edge 23 and its trailing edge 24. The blade 2a may include a foot 26. The blade 20 may include a first longitudinal end connected to the blade foot 26 and a second longitudinal end, opposite the first longitudinal end, free and configured to form a blade tip 25. The blade 2a may also include a reinforcement or shield 3 for the protection of the leading edge 23, in the form of a metallic plate. In the example, the shield 3 extends vertically (relative to axis A) and along a portion of its length (relative to axis B) from the leading edge 23 of the blade 20 to the lower surface 21 and the upper surface 22. The protective shield 3 may be made of titanium or any other metallic material. However, part 10 of the invention is not limited to the fan blade 2, 2a, 2b of the enclosed turbomachine 1,and can also be applied to other types of blades made of composite material (such as fixed or moving blades of low-pressure compressors 1b and high-pressure compressors 1c, and of high-pressure and low-pressure turbines of the turbomachine 1). Generally, the invention can be applied to any composite material parts requiring treatment and / or having one or more components made of different materials (such as metallic foil on the leading edge or a "wear strip" type coating for a turbomachine blade). By way of example, these parts could be propellers of an unfaired turbomachine, turbomachine casings, a turbomachine or aircraft panel, etc. The treatment process according to the invention comprises a step (b) of removing at least one layer 100 covering a surface 12 of the part 10 (which can be the blade 2, 2a, 2b),in order to prepare (in particular in order to remove and / or clean) at least part of this layer 100. According to one of the features of the invention, the treatment process comprises, before the stripping step (b), a scarification step (a) of at least one layer 100 of the part 10. In particular,Part of the thickness of layer 100 can be scarified in step (a). At least one layer 100 of part 10 is an anti-erosion layer 214. The anti-erosion layer can be a multilayer comprising, for example, a first sub-layer 210 (e.g., a bonding layer) and a second sub-layer 214 (e.g., an anti-erosion layer). The second sub-layer 214 can extend above or below the first sub-layer 210. The first sub-layer 210 can be epoxy and the second sub-layer 214 can be polyurethane. Figure 3 summarizes the steps of the treatment process of the invention, with optional steps indicated by dashed lines. Step (a), scarification, initiates the stripping process to facilitate the removal of material (namely, layer 100) during step (b), stripping. For example,Scarification creates incisions in layer 100 of part 10. Step (a) of scarification can be performed on the entire layer 100 to be treated. This allows the incisions to be distributed across the entire layer to facilitate and speed up material removal during pickling. Step (a) can be carried out by projecting a water jet 54 at a first parameter (such as a predetermined first pressure P1). The water jet can be an effective means of material removal (or machining) to remove the necessary material without damaging the part. The water jet 54 can be projected at high pressure. The first pressure P1 can be between 1500 and 2000 bar. Preferably, this first pressure P1 can be between 1500 and 1800 bar. During step (a), a predetermined thickness can be scarified. This thickness can be a maximum of 2.00 mm. In other words,The thickness of each of the incisions formed by the scarification on layer 100 can be a maximum of 2.00 mm. The thickness of the incisions can vary depending on the composite material, the layer(s) to be removed, and / or the dimensions of layer 100 to be treated. Advantageously, the scarified thickness of layer 100 can be a maximum of the thickness of an anti-erosion layer 214 covering the part 10. For example, the scarified thickness of layer 100 can be a maximum of approximately 150 µm. After step (a), the stripping step (b) allows, for example, the easy and rapid removal of material from layer 100 to be treated, without altering the part 10 and / or its components (such as a bonding layer 210,a polyurethane film 212 and / or the protective shield 3 in the case of the blade 2 (particularly with reference to Figure 5 or Figure 6). Step (b) can be carried out by projecting the water jet 54 at a second parameter (such as a second pressure P2). The second parameter can vary and / or adjust according to, in particular, the indication in an inspection step (i). The second pressure P2 can be between 1000 and 2000 bar. Preferably, this second pressure P2 can be between 1000 and 1500 bar. The first pressure P1 can be different from the second pressure P2. In particular, the first pressure P1 can be higher than the second pressure P2. This makes it possible, in particular, to effectively form incisions in the layer 100 to be treated during step (a) and then, for example, to easily and quickly remove material from this layer during step (b). The first pressures P1 and second pressures P2 may vary depending on the composite material.of the layer(s) to be removed and / or the dimensions (such as thickness, profile, etc.) of the layer to be treated. The water jet 54 may be demineralized (or tap water) and non-abrasive. For example, the water jet may have a conductivity of 2500 μS / cm or less at a temperature of 20°C. The water jet 54 projected during step (a) may be similar to that projected during step (b). With reference to Figure 4, this application will now describe an example of an apparatus (or machine) for carrying out steps (a) and (b). This apparatus may include the water jet 54 projected onto the layer 100 to be treated. The water jet 54 may pass through a high-pressure pump 50, be compressed through a nozzle 52, and be projected onto the part 100 to be treated. In particular, the water jet 54 can be projected by a single nozzle 52,A multi-nozzle (or, in other words, a nozzle with several spray heads) or a nozzle with multiple sapphire tips. The multi-nozzle allows, in particular, the simultaneous treatment of the same layer 100 or several layers 100 of the part. For example, the water jet 54 can be projected, preferably simultaneously, onto the intrados 21 and extrados 22 surfaces of the blade 2. As an example, a sapphire-type nozzle can be marketed under the reference "KMT 4000 bar Water Jet, Aqualine Heads, Sapphire Nozzles". The nozzle 52 can be moved by a numerically controlled device 56 (such as a computer). The nozzle 52 can be positioned at a distance D from the layer 100 to be treated. This distance D can vary and / or be adjusted, notably according to the instructions in step (i). The distance D can be between 50 and 100 mm. Preferably, this distance D can be between 50 and 80 mm. Even more preferably,The distance D can be between 60 and 80 mm or between 50 and 70 mm. A measuring device 58 can be connected to the nozzle 52 or the multi-nozzle to check the layer 100 of the part. This measuring device 58 can be a camera or a sensor (for example, for measuring the thickness to be scarified and / or stripped). Before or after step (b), the treatment process according to the invention may further include a step (i) of inspecting the layer 100. This step (i) can perform several checks, such as: - the presence or absence of any residues of the layer 100, - the quantity of material removed and / or scarified, and / or - the presence or absence of damage to the final layer 100 of the part 10. The term "final layer" refers to the treated (or otherwise stripped) surface of the part after scarification and stripping. Step (i) can be performed by measuring device 58. Alternatively,Step (i) can be performed manually by the operator, for example, by visual inspection. The treatment process according to the invention may include, after the stripping step (b), a deposition step (c), for example, of an additional coating 4 or the shield 3 on the stripped surface 12 (corresponding in particular to the external surface 12 of the part 10 without part or all of the layer 100). The addition of this coating 4 can make it possible to touch up or repair, for example, a damaged area of ​​the part, or to integrate an additional function into the part (such as a protective function, for example, with the protective shield 3). Scarification and / or stripping can be optimized by varying at least one of the following parameters: - the pressure P1, P2 of the water jet 54, - the movement speed of the nozzle 52, - the scarification and / or stripping strategy, such as the machining path (straight path, curved path,in a crenellated or zigzag pattern; with or without sweeping; rotation or translation of the nozzle 52, etc.), - the number of passes of the nozzle 52 over the same layer 100, - the distance D between the nozzle 52 and the layer 100, - the flow rate of the water jet 54, - the pitch or forward speed of the nozzle 52 relative to the workpiece, - the dimensions of the nozzle 52 (such as its diameter), and / or - the angle of orientation of the nozzle 52 relative to the layer 100 to be treated. Figure 5 illustrates a first example of a turbine blade 2 of a turbomachine 1 comprising the intrados 21 and extrados 22 faces to be treated. This blade 2 may include carbon fibers embedded in epoxy. The blade 2 may include a polyurethane film 212 located on the intrados face 21 and an anti-erosion layer 214 around the polyurethane film 212,and possibly an adhesion layer 210 intercalated between the polyurethane film 212 and the anti-erosion layer 214. This blade 2 may include the adhesion layer 210 located on the extrados face 22 and the anti-erosion layer 214 around this adhesion layer 210. In particular, the anti-erosion layer 214 is located on the adhesion layer 210 on the side of the intrados faces 21 and extrados faces 22 (figure 5). According to another variant not shown in the figures, the anti-erosion layer 214 is located, on the one hand, on the tack layer 210 on the upper surface 22, and on the other hand, on the polyurethane film 212 on the lower surface 21. In Figure 5, the various layers 210, 214 and the polyurethane film 212 can each have a homogeneous and uniform thickness along the lower surface 21 and upper surface 22. The tack layer 210 can be a resin,such as epoxy. The 214 anti-erosion coating can be a multi-layer coating, for example, applied by painting. This 214 anti-erosion coating may comprise a first, or base, layer of epoxy and a second, or top, layer of polyurethane. The 214 anti-erosion coating may provide erosion protection, particularly with a "wear strip" type coating, and potentially a damping function, notably through the use of polyurethane. The 214 anti-erosion coating may have a maximum thickness of 150 µm. The first table (Table 1) summarizes the parameters of steps (a) and (b) by water jet projection which can be used on the extrados face 22 of the blade 2 in Figure 5, for example to remove layer 100 which can be the anti-erosion layer 214. [Table 1] step (a) scarification step (b) stripping nozzle travel speed between 100 and 200 between 100 and 200 (mm.s, -1Water jet pressure (bars) between 1500 and 1800 between 1000 and 1500 Distance between nozzle and layer to be treated (mm) between 50 and 70 between 50 and 70 Number of nozzle passes 1 1 or 2 The second table (Table 2) summarizes the parameters of steps (a) and (b) that can be used on the underside 21 of the blade 2 in Figure 5, for example, to also remove layer 100, which can be the anti-erosion layer 214. [Table 2] Step (a) scarification Step (b) stripping Nozzle travel speed (mm.s) between 200 and 500 between 100 and 500 -1Water jet pressure (bars) between 1500 and 2000 between 1000 and 2000 Distance between nozzle and layer to be treated (mm) between 60 and 80 between 60 and 80 Number of nozzle passes 1 or 2 between 1 and 10 The parameters in the first and second tables can be used to obtain a clean final layer, without residue and without damaging blade 2. At the end of step (b), the condition of the final layer of blade 2 on the side of the lower surface 21 and / or upper surface 22 can be checked by performing step (i). Figure 6 illustrates a second example of turbine blade 2 of a turbomachine 1 with the lower surfaces 21 and 22 to be treated. Blade 2 according to this second example differs from blade 2 of the first example (figure 5) by a heterogeneous profile of the layers covering the intrados 21 and extrados 22 faces. This blade 2 may include carbon fibers embedded in epoxy.On the lower surface side, the blade 2 in this second example may include an adhesive layer 209 of the polyurethane film 212 located on the lower surface 21, the polyurethane film 212 surrounding this adhesive layer 209, and a finishing layer 216 (such as the anti-erosion layer 214), and optionally the tack layer 210 sandwiched between the finishing layer 216 and the polyurethane film 212. On the upper surface side, the blade 2 in the second example may include the tack layer 210 located on the upper surface 22 and the finishing layer 216 (such as the anti-erosion layer 214) surrounding this tack layer 210. The various layers 209, 210, 214, 216 and the polyurethane film 212 may each have a different thickness from the other layers 209, 210, 214, 216. and / or heterogeneous and irregular along the intrados 21 and extrados 22 faces.Advantageously, the treatment process can be carried out on part 10, which can be blade 2, in particular for at least one of the following uses: - preparing one or more layers 100 of part 10 in particular before deposition of the coating 4 or the protective shield 3, - repairing one or more damaged areas of layer 100, - touching up one or more layers 100 of the part, and - cleaning at least one component of part 10 (such as the protective shield 3, the polyurethane film 214, etc.).

Claims

CLAIMS 1. A method for treating a part (10) made of composite material, in particular for an aircraft turbomachine (1) or for an aircraft, the part (10) comprising at least one layer (100) covering a surface (12) of this part (10), this method comprising a step (b) of stripping the at least one layer (100) of the part (10) so as to prepare at least part of said at least one layer (100), characterized in that prior to the stripping step (b), the method comprises a step (a) of scarifying the at least one layer (100) of the part (10), so as to initiate the stripping by creating incisions on the layer (100), and in that the at least one layer (100) of the part (10) is an anti-erosion layer (214). 2.A treatment method according to claim 1, characterized in that the erosion control layer (214) is a multilayer comprising a first sublayer (210) and a second sublayer (214), the second sublayer (214) extending above or below the first sublayer (210).

3. A treatment method according to claim 1 or 2, characterized in that the first sublayer (210) is made of epoxy, and the second sublayer (214) is made of polyurethane.

4. A treatment method according to any one of claims 1 to 3, characterized in that the scarification step (a) is carried out over the entirety of at least one layer of the part.

5. A treatment method according to any one of claims 1 to 4, characterized in that the steps (a, b) of scarification and stripping are carried out by projecting a water jet (54) at, respectively, a predetermined first pressure (P1) and a second pressure (P2). 6.A treatment process according to claim 5, characterized in that the first pressure (P1) is greater than the second pressure (P2).

7. A treatment process according to claim 5 or 6, characterized in that the first pressure (P1) is between 1500 and 2000 bar, and the second pressure (P2) is between 1000 and 2000 bar.

8. A treatment method according to any one of claims 5 to 7, characterized in that the water jet (54) is demineralized and abrasive-free.

9. A treatment method according to any one of claims 5 to 8, characterized in that the water jet (54) is projected by a single nozzle (52), a multi-nozzle system, or a nozzle comprising several sapphires.

10. A treatment method according to any one of claims 1 to 9, characterized in that, before and / or after the stripping step (b), the method further comprises a step (i) of inspecting at least one layer (100) of the workpiece.

11. A treatment method according to claims 9 and 10, characterized in that a measuring device (58), for example, a camera or a sensor, is connected to the nozzle (52) or the multi-nozzle system so as to check at least one layer (100) of the workpiece. 12.A treatment method according to any one of claims 1 to 11, characterized in that the stripping step (b) is followed by a step (c) of depositing an additional coating (4) or a protective shield (3) onto the stripped surface (12).

13. A treatment method according to any one of claims 1 to 12, characterized in that the turbomachine (1) or aircraft part (10) is a blade (2), for example, of a fan, or a casing.

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