Method for holding a de-icing or Anti-icing electrical conductor on a turbomachine blade

Abstract

The invention relates to a method for manufacturing a turbomachine blade (9), the method comprising: manufacturing a body by forging, casting, machining and / or additive manufacturing; and placing an electrical conductor (32; 132) on the body; and covering the electrical conductor by cold gas dynamic spraying of a metallic powder through at least one orifice (50) in a plate (48) arranged substantially parallel to and facing the electrical conductor. The invention also relates to a device for holding a substrate, such as a turbomachine blade, for cold gas dynamic spraying of a metallic powder onto the substrate. The invention also relates to a turbomachine blade characterized in that it is manufactured according to the method of the invention.

Description

[0001] Description

[0002] METHOD FOR RETAINING AN ELECTRICAL DE-ICING OR ANTI-ICING CONDUCTOR ON A TURBOMACHINE BLADE

[0003] technical field

[0004] The invention relates to de-icing systems for turbomachine blades.

[0005] Previous art

[0006] The invention relates more particularly to aspects related to the efficiency and safety of aircraft turbomachine compressors. Indeed, within the primary runner and at the inlet of the low-pressure compressor (also commonly called "booster") there is a set of stator straightening vanes (also called IGV for "Inlet Guide Vane").

[0007] During certain phases of flight and on the ground, atmospheric conditions may be encountered that are conducive to the formation of frost or ice on the turbine blades. When this occurs, it can lead to partial or total obstruction of the primary flow, and to the ingestion of ice blocks that break off from the primary flow. Indeed, an obstruction of the primary flow results in insufficient fuel supply to the combustion chamber, which can then shut down or prevent the turbomachine from accelerating.

[0008] The published patent document EP 3 228 834 A1 discloses an aeronautical turbomachine comprising a compressor blade equipped with an electrical de-icing device incorporating a thermistor. The solution proposed in this document offers room for improvement in terms of manufacturing process and heat conduction efficiency to achieve even more effective de-icing.

[0009] Summary of the invention

[0010] Technical problem

[0011] The invention aims to provide a simple and economical manufacturing process for obtaining a blade with effective de-icing and anti-icing properties. Technical solution

[0012] The invention is the result of technological research aimed at significantly improving aircraft performance and, in this respect, contributes to reducing the environmental impact of aircraft. To this end, the present invention relates to a method for manufacturing a turbomachine blade, the method comprising:

[0013] - the manufacture of a body by forging, casting, machining and / or additive manufacturing; and

[0014] - the placement of an electrical conductor on the body; and

[0015] - the coating of the electrical conductor by dynamic projection with cold gas of a metallic powder through at least one orifice of a plate arranged substantially parallel and opposite the electrical conductor.

[0016] Dynamic cold gas projection of a metallic powder has many advantages: it ensures good thermal conductivity in the blade; ensures a surface finish compatible with the manufacturing constraints of a blade; and guarantees good durability against fatigue and / or corrosion.

[0017] Preferably, the metallic material consists of aluminum filled with silicon carbide and / or alumina and / or contains other fillers, for example, mineral fillers. These materials are suitable for the spray manufacturing process, are good thermal conductors, and are lightweight. Preferably, the metallic material consists primarily of aluminum from the 1xxx series (with at least 99% aluminum), the 2xxx series (with copper as the main alloying element), the 6xxx series (with magnesium and silicon as the main alloying elements), or the 7xxx series (with zinc and magnesium as the main alloying elements).

[0018] According to an advantageous embodiment of the invention, the electrical conductor is completely covered by a second dynamic cold gas projection through a single orifice of a second plate, said method further comprising holding the electrical conductor on the body by means of a first dynamic cold gas projection of a metallic powder through a succession of orifices of a first plate, prior to the total covering of the electrical conductor by the second projection.

[0019] Advantageously, each of the first and second plates forms a stencil for the metallic powder projected towards dawn.

[0020] According to an advantageous embodiment of the invention, the first dynamic projection is through a succession of orifices in the first plate, so as to form anchoring bridges in projected metallic powder fixing the electrical conductor to the body of the blade.

[0021] Advantageously, the body fabrication process includes forming a channel within the body, the placement step being such that the electrical conductor is positioned within the channel. Preferably, the channel comprises a U-shaped, V-shaped, or Y-shaped funnel profile. Such a profile is simple to manufacture and helps to hold the conductor in position before and during the encapsulation process. The channel preferably corresponds to a groove.

[0022] According to an advantageous embodiment of the invention, the anchoring brackets fix the electrical conductor against a bottom of a path of said electrical conductor formed in the body.

[0023] According to an advantageous embodiment of the invention, the retention of the electrical conductor on the body comprises a plating of said conductor by pins extending from the first plate, prior to and during the first dynamic projection forming the anchoring bridges.

[0024] According to an advantageous embodiment of the invention, each of the succession of orifices of the first plate and of the orifice of the second plate, extends along a trajectory defined by the path on the blade.

[0025] Advantageously, at least one orifice, corresponding to a single orifice or a succession of orifices, describes on the corresponding plate a trajectory identical to that described by the shape of the electrical conductor on the blade.

[0026] According to an advantageous embodiment of the invention, the coating is such that the metallic material resulting from the dynamic cold gas projection of a metallic powder fills the path to become flush with an outer surface of the blade. According to another advantageous embodiment of the invention, the blade is held by a corresponding mounting platform, and the plate is disposed on a receiving face of the platform.

[0027] According to an advantageous embodiment of the invention, the method comprises a change of the first plate by the second plate on the platform, between the first projection and the second projection.

[0028] According to an advantageous embodiment of the invention, the retention of the electrical conductor on the body is ensured by at least one of the following means: gluing; brazing; over-sheathing; placement of bridges; tamping of the body; tamping of the electrical conductor; vacuuming; magnetizing of the electrical conductor; use of a wheel combined with the cold gas projection tool; micro-welding.

[0029] Preferably, the retention of the electrical conductor on the body is a retention in position of said electrical conductor in the corresponding groove.

[0030] The retention of the electrical conductor on the body can be achieved in combination with the first dynamic cold gas projection of the metal powder through the succession of orifices of the first plate, or said retention of the electrical conductor on the body can alternatively be in place of the first dynamic projection.

[0031] According to an advantageous embodiment of the invention, the retention of the electrical conductor on the body and the covering of said electrical conductor are ensured by means of a device according to the invention.

[0032] The invention also relates to a substrate support device for dynamic cold gas projection of a metallic powder onto said substrate, notable in that said device comprises a substrate support platform, such as a turbomachine blade, and at least one plate intended to be mounted on said platform to extend substantially parallel to an outer surface of said substrate, the at least one plate comprising at least one orifice configured to be disposed opposite a path opening onto said outer surface and comprising an electrical conductor, said at least one orifice being configured to allow the passage of a metallic powder projected by dynamic cold gas projection towards said path, so as to at least partially cover the electrical conductor, said device being adapted to a method according to the present invention.

[0033] Preferably, the substrate comprises the turbomachine blade manufactured by the manufacturing process according to one of the advantageous modes of the invention.

[0034] According to an advantageous embodiment of the invention, at least one orifice extends along a trajectory defined by the path on the substrate.

[0035] Preferably, at least one orifice extends over at least one plate in a serpentine shape comprising at least one U-shaped portion. Alternatively, the path and the corresponding orifice may extend in a straight line.

[0036] According to an advantageous embodiment of the invention, at least one plate comprises a first plate and a second plate configured for sequential use with said platform.

[0037] According to an advantageous embodiment of the invention, the first plate forms a succession of orifices which follow the path of the track, so that the metallic powder projected through said succession of orifices forms a succession of anchoring bridges capable of holding the electrical conductor against a track bottom.

[0038] Preferably, partial coverage of the electrical conductor is ensured by anchoring brackets.

[0039] According to an advantageous embodiment of the invention, the first plate comprises studs made of material with said first plate, said studs being configured to extend in the path so as to press the electrical conductor against the bottom of said path.

[0040] According to an advantageous embodiment of the invention, each pin is formed between two adjacent orifices of the succession of orifices.

[0041] Preferably, the spikes comprise protrusions projecting from an underside of the first plate opposite an upper side facing the metal powder projected during dynamic cold gas projection. According to an advantageous embodiment of the invention, each orifice in the sequence of orifices is separated from an adjacent orifice by a distance corresponding to at most twice the average length of each of said orifices.

[0042] According to an advantageous embodiment of the invention, the succession of orifices extends at regular intervals along a whole extent of the path on the substrate.

[0043] According to an advantageous embodiment of the invention, the second plate comprises a single orifice which follows a trajectory defined by the path on the substrate, said orifice extending continuously over said second plate along a total extent of said path on the substrate.

[0044] According to an advantageous embodiment of the invention, at least one plate is configured to be mounted on the platform by means of threaded guide pins projecting from a receiving face of said platform, and wing nuts intended to tighten at least one plate by an engagement of said nuts with the threaded guide pins.

[0045] According to an advantageous embodiment of the invention, the first plate is split into two parts configured to come together on the receiving face and constitute said first plate.

[0046] According to an advantageous embodiment of the invention, the substrate corresponds to a turbomachine blade, and the outer surface is the intrados or extrados of said blade. Said outer surface preferably includes the leading edge and / or the trailing edge. Alternatively, the electrical conductor is placed at least partially at the leading edge of the blade.

[0047] The invention also relates to a turbomachine blade comprising an electrical conductor, notable in that said blade is obtained by the manufacturing process of a turbomachine blade according to the present invention.

[0048] According to an advantageous embodiment of the invention, the electrical conductor comprises at least one electrical line encased in an insulating sheath. This at least one line may correspond to a single electrical line passing through the blade, or may correspond to two lines that can be joined at one end of the conductor to close the electrical circuit. Preferably, with the exception of the electrical conductor and the metallic material, the blade is made of a simple aluminum alloy or primarily of an aluminum-based metal matrix composite (MMC).

[0049] The invention also relates to a turbomachine compressor comprising a blade, the compressor being notable in that the blade is according to the invention, or is manufactured at least partially by the process according to the invention.

[0050] The invention also relates to a method of retaining an electrical conductor on a turbomachine blade, comprising a step of placing the electrical conductor on a body of the blade, remarkable in that said method further comprises a step of coating said electrical conductor by dynamic projection with cold gas of a metallic powder through at least one orifice of at least one plate of the device according to the invention.

[0051] Advantageously, the coating of the electrical conductor by dynamic cold gas projection of a metallic powder comprises a first projection through at least one orifice to form anchoring bridges on the electrical conductor, and successively comprises a second projection through said at least one orifice to completely cover said electrical conductor.

[0052] It is understood that each detail of one embodiment above can be combined with each other detail of the other embodiments.

[0053] Benefits provided

[0054] The manufacturing process according to the present invention advantageously allows the electrical conductor to be held against the bottom of the path on the body, by means of at least one plate of the holding device, and this, prior to and during the cold spray projection.

[0055] Indeed, the contact created by the studs of the first plate, as well as by the anchoring points formed by the first cold spray application, ensures effective retention of the conductor against the blade body. This prevents any air gap between the conductor and the blade body when the electrical conductor is completely covered during the second cold spray application. Thus, the turbomachine blade according to the present invention is robust and exhibits improved thermal conductivity towards the underside, thereby significantly enhancing the blade's efficiency and de-icing performance.

[0056] The metallic coating applied to the electrical conductor by dynamic cold gas spraying ensures improved thermal conduction between the conductor and the blade body, thanks to the absence of porosity and the careful selection of materials. This material combination also guarantees mechanical and metallurgical compatibility, as well as increased conductor durability, protecting it against fatigue and impacts. Furthermore, it allows for continuous surface protection, thus preventing corrosion and erosion, while also enabling effective blade de-icing, even under extreme conditions (at -40°C and an airflow velocity of approximately 800 km / h). In addition, the blade is also capable of effectively preventing ice formation on its outer surfaces.

[0057] The present invention improves the performance of aircraft compressors and the efficiency of turbomachinery, thereby reducing fuel consumption and greenhouse gas emissions. The cold gas spraying process allows for material deposition without damaging either the driver or the blade, ensuring good mechanical and physicochemical adhesion between the materials involved.

[0058] Brief description of the drawings

[0059] Figure 1 illustrates a cross-sectional view of a compressor of a turbomachine comprising a blade according to the invention;

[0060] Figure 2 represents a method for manufacturing the blade of Figure 1 according to the invention;

[0061] Figure 3 illustrates a cross-sectional view of the blade of Figure 1 along axis AA, said blade comprising an electrical conductor entirely covered by dynamic cold gas projection of a metallic powder;

[0062] Figure 4A represents a partial perspective view of a cable corresponding to the electrical conductor of the blade in Figure 3, according to a first embodiment; Figure AB represents a partial perspective view of a cable corresponding to the electrical conductor of the blade in Figure 3, according to a second embodiment;

[0063] Figure 5 illustrates an enlarged cross-sectional view of the cable of Figure 4A arranged in a corresponding path of the blade of Figure 3;

[0064] Figure 6 represents an exploded and perspective view of a device according to the invention adapted to the manufacturing process of the blade according to the invention, showing the blade prior to the cable covering;

[0065] Figure 7 represents the device of Figure 6 comprising a first plate having a succession of orifices allowing the passage of the projected metallic powder towards the cable in the path of the blade;

[0066] Figure 8 illustrates a cross-sectional view along an axis BB passing through the blade and the first plate to a portion of said plate comprising pins arranged between two adjacent orifices;

[0067] Figure 9 illustrates an enlarged cross-sectional view of the cable held against a bottom of the blade path by means of anchor brackets formed by a first dynamic projection through the succession of holes of the first plate of Figure 7;

[0068] Figure 10 represents an exploded and perspective view of the device according to the invention, showing the blade after partial covering of the cable by means of the anchoring brackets;

[0069] Figure 11 illustrates an enlarged cross-sectional view of the cable completely covered by the metallic material formed by a second dynamic projection through an orifice of a second plate of the device of Figure 10.

[0070] Detailed description of the implementation methods

[0071] In the following description, the terms "internal" and "external" refer to positioning relative to the axis of rotation of an axial turbomachine. The axial direction corresponds to the direction along the turbomachine's axis of rotation, with lengths measured axially. Widths are measured circumferentially. The radial direction is perpendicular to the axis of rotation. Upstream and downstream refer to the main flow direction within the turbomachine. The figures are not drawn to scale, and in particular, thicknesses and radial dimensions are exaggerated for ease of reading.

[0072] Figure 1 represents a cross-sectional view of a compressor 2 of an axial turbomachine 4.

[0073] Turbomachine 4 can correspond to a turbofan engine, turbojet, turbofan, turboprop, turboshaft engine, or any other type of two-flow turbomachine. Alternatively, turbomachine 4 can correspond to a multi-flow turbomachine, such as a counter-rotating open rotor (CROR or unducted single fan) turbofan, or any other triple-flow turbomachine.

[0074] Preferably, the compressor 2 is either a low-pressure compressor or a high-pressure compressor (not shown). The turbomachine 4 also includes other components not shown in Figure 1, such as a high-pressure compressor, a combustion chamber, and one or more turbine stages. The turbine(s) drive a rotating rotor 6. The rotor supports several rows of rotor blades 8 associated with rows of stator blades 10. The rotation of the rotor 6 around its axis of rotation X thus allows the airflow to be progressively compressed to the inlet of the combustion chamber.

[0075] A fan 12 (partially illustrated) is coupled to the rotor 6 and generates an airflow that splits into an internal radial flow F1, commonly called the primary flow F1, and an external radial flow F', which can correspond to a secondary flow F' in a dual-flow turbomachine, or a tertiary flow F' in a triple-flow turbomachine 4. The primary flow F1 and external flow F' are separated by a separation nozzle 14.

[0076] The rotor blades 8 can extend radially from a rotor support 16 which can be of drum type (one-piece bladed drum or any other type of support for a rotor).

[0077] The stator vanes 10 extend essentially radially from an outer casing 18. They can be fixed and secured to it by means of mounting pins 20. They pass radially through the primary flow F1. The low-pressure compressor 2 includes, at the inlet of the primary flow stream F1 22, a row of stator vanes 9 that can be fixed or have variable pitch, commonly referred to as VSV vanes (for "Variable Stator Vane"). The variable pitch of the vanes 9 can be achieved by means of an actuation system (not shown) regulating the angle formed by the vanes 9 around an axis 24.

[0078] Each blade 9 comprises a blade 11 and two bases 26 arranged at the two ends of the blade 11. Each base 26 is provided with a trunnion 28 ensuring a pivot connection with the housings 18, 30, the bases 26 being housed in recesses 31 of these housings 18, 30. An outer surface 18.1 and a lower guiding surface 30.1 delimit the groove 22.

[0079] In this upstream part of the turbomachine, certain elements are subject to frost. Thus, blade 9 of the invention includes a means of de-icing and anti-icing.

[0080] The invention is not limited to VSV 9 blades but can also be applied to other blades, VSV or not, statorized or not.

[0081] Figure 2 represents a process 100 for manufacturing the blade 9 of Figure 1. The process is "partial" in the sense that other steps may occur, before or after those described here.

[0082] Process 100 includes a first step 102 corresponding to the fabrication of the blade body by at least one of the following manufacturing techniques: forging, casting, molding, machining, fiber braiding, and / or additive manufacturing. For example, the forged or cast blade may be machined to obtain the appropriate manufacturing tolerances. Or the blade may be entirely obtained by additive manufacturing with or without further machining.

[0083] The blade of the present invention may be primarily made of a metal matrix composite material. Preferably, the blade is made of a simple aluminum alloy or primarily of an aluminum-based metal matrix composite (MMC). Alternatively, the blade may be made entirely of titanium. As another alternative, the blade may be made from a titanium-based composite material, for example, a titanium alloy of the TA6V type.

[0084] Step 102 of manufacturing the blade body may include the creation of an optional path preferably forming a groove in the blade body and extending in particular along the blade, said groove opening onto the extrados or the intrados of the blade.

[0085] Alternatively, the blade body may lack a channel for the de-icing electrical conductor, which can then be laid directly on the outer surface of the body. Alternatively, the channel may partially form a groove (narrow channel) for the conductor, combined with one or more sections wider than the conductor's cross-section.

[0086] The process 100 then includes a step 104 of installing an electrical conductor on the blade body manufactured in step 102. This installation may consist of simply manually placing the electrical conductor on the body, preferably in the corresponding groove. The electrical conductor preferably corresponds to a heated electric cable suitable for defrosting the blade and preventing ice formation.

[0087] Step 106 is an optional operation involving holding the cable before and / or partially during its metal covering. Step 108 involves covering the conductor with sprayed metal. These steps will be explained in detail later in this description.

[0088] Figure 3 illustrates a cross-sectional view of the blade of Figure 1 along axis AA, in which the electrical cable 32 is completely covered by dynamic cold gas projection of a metallic powder.

[0089] The blade 11 of the blade 9 comprises a leading edge 11.1 and a trailing edge 11.2, as well as an intrados 11.3 and an extrados 11.4 extending from the leading edge 11.1 to the trailing edge 11.2. The electrical cable 32 constituting the electrical de-icing conductor extends preferentially over the intrados 11.3 and following a sinuous path corresponding substantially to a spiral and / or serpentine pattern visible in figures 6 and 10.

[0090] We can see that the blade 9 includes a groove 40 receiving the cable 32. This allows to increase the thermal conductivity towards the intrados 11.3 and the extrados 11.4 since the cable 32 is embedded in the blade 9. Preferably, the depth of the groove 40 is constant over the whole of the blade.

[0091] The groove 40 is covered by a filling material 42 advantageously corresponding to a metallic powder forming a metallic coating 42 around the cable 32 and is flush with the intrados 11.3. This metallic coating 42 is obtained by dynamic cold gas projection of a metallic powder in steps 106 and 108 of the process 100 of figure 2.

[0092] Cold spray, also known by its English name, is a coating application process using powder suspended in a gas projected at high speed (up to 800 m / s) and deforming upon impact. Cold spray is achieved using an inert gas (nitrogen and / or helium) or air pressurized to up to 60 bar and heated to between 500°C and 1100°C. Patent application PCT / EP2023 / 079744 describes the principle of metallic material formation by the cold spray process on a substrate, such as a turbomachine blade.

[0093] Figure 4A represents a partial perspective view of the cable 32 according to a first embodiment in which said cable 32 comprises two electrical lines 34 corresponding to two heated metal wires 34 which are covered with an insulating layer 36, the latter preferably being made of magnesia powder allowing to electrically insulate the two wires 34 in order to allow only a diffusion of thermal energy towards the blade of the blade of the invention.

[0094] The wires 34 and the insulating layer 36 are covered with a protective metal sheath 38, said sheath 38 being made of stainless steel, aluminum alloy, or Inconel® (a superalloy containing primarily nickel). For this purpose, the cable 32 is advantageously a shielded resistive cable. The diameter of the sheath 38 can be from approximately 0.5 mm to 2 mm. The cable 32 according to the first embodiment allows for a "spiral" pattern terminating in a free end thanks to the two electrical lines 34 that can be connected together at the distal end of the cable 32. Whereas the cable 132 according to the second embodiment illustrated in Figure 4B comprises only one line 34. The cable 32 therefore cannot have a free end on the blade and requires a return of said cable 132, for example, to the base at the blade tip or the blade root.

[0095] Figure 5 illustrates an enlarged cross-sectional view of figure 3, showing in particular the cable 32 in its groove 40.

[0096] Preferably, the groove 40 includes a hemispherical base 43, having a diameter equal to or slightly greater than the external diameter of the cable 32. The base 43 may alternatively be straight.

[0097] The 32 cable can optionally be over-sheathed to protect it even more during the cold spray stage or to facilitate holding the cable by deformation of the sheath or to limit the number of materials in contact.

[0098] The groove 40 includes flanks 41 which can be straight (visible as dotted lines in Figure 5), so that the profile of the groove 40 is a U, as illustrated in Figure 3. Alternatively, the profile of the groove can be V-shaped (visible as dotted lines) or Y-shaped of the funnel type, the latter being the preferred profile of the groove 40.

[0099] A Y shape allows better adhesion of particles projected by cold spray, while ensuring lateral pre-holding at the bottom 43. Preferably, the side walls of the Y groove 41 have an inclination with respect to the direction perpendicular to the intrados 11.3 which is between 5° and 85°.

[0100] The present invention advantageously allows the cable 32 to be held against the bottom 43 of the groove 40, so as to avoid any hollow (air) area between the blade 9 and the cable 32, after the groove 40 has been covered by cold spray. Indeed, hollow areas in the groove correspond to void areas forming cavities which impair the overall robustness of the turbomachine blade, and which negatively impact the thermal conductivity towards the intrados 11.3, and therefore the de-icing or anti-icing efficiency.Advantageously, the method of the invention, comprising the use of a device 44 (visible in figure 6) for holding a substrate for dynamic cold gas projection of a metallic powder, allows, by means of at least one orifice in a plate configured for the passage of the projected powder towards the groove, to cover at least partially the electrical conductor by anchoring bridges (formed by said powder) prior to total covering of the groove.

[0101] Figure 6 shows an exploded and perspective view of the device 44 adapted to the manufacturing process 100 for the blade 9 according to the invention. Here, the blade 9 is schematically illustrated prior to the covering of the cable 32.

[0102] The device 44 comprises a substrate mounting platform 46, preferably corresponding to the blade 9, having a cavity 46.1 with a retaining face 46.2 receiving the blade 11 of the blade 9, and a receiving face 46.3 receiving a first plate 48 intended to be mounted on the platform 46 to extend substantially parallel to the intrados 11.3 and may contact the latter. The plate 48 comprises a series of orifices 50 configured to be arranged opposite the groove 40. The functions of the first plate 48 will be detailed in Figure 7. The term "substantially parallel" corresponds to a configuration where the first plate 48 is perfectly parallel to the intrados 11.3 or to the chord of the blade 9, or in which the first plate 48 is inclined relative to the intrados 11.3 by no more than 20°.

[0103] The device 44 preferably includes threaded guide pins 45 projecting from the receiving face 46.3; these may correspond to screws or bolts which allow the plate 48 to be held tightly against said face 46.3 by means of wing nuts 49. Clamping means 47 may ensure that the blade 9 is held in position in the cavity 46.1.

[0104] Preferably, the first plate 48 is split into two parts 48.1, 48.2 configured to meet on the receiving face 46.3 and constitute said first plate 48 as illustrated in figure 7.

[0105] With reference to Figure 7, each of the orifices 50 is positioned opposite the groove 40 so as to allow the projected metal powder to pass directly towards the cable. Advantageously, the orifices 50 follow a path along the groove 40 so that the metal powder projected through said orifices 50 forms a series of anchoring lugs 42.1 (visible in Figure 9) capable of holding the electrical cable against the bottom of the groove 40.

[0106] In this regard, each orifice 50 is preferentially distant from an adjacent orifice 50 by a distance "d" corresponding to at most twice the average of the extent "e" of each of said orifices 50. The extent e being measured along a direction defined by the trajectory of the groove 40. The successive orifices 50 may comprise an identical or variable extent e.

[0107] Preferably, the orifices 50 are arranged at regular intervals along the extent of the groove 40. The distance d can correspond to a width of a pin extending from an underside of the first plate 48 between two adjacent orifices 50.

[0108] Figure 8 illustrates a cross-sectional view along an axis BB passing through the blade 9 and the first plate 48 to a portion where it includes pins 52 arranged between two adjacent orifices.

[0109] Preferably, between each two adjacent orifices of the first plate 48, a pin 52 extends from the lower face 48.5 opposite an upper face 48.4 intended to receive the sprayed powder. For this purpose, the material constituting the plate 48 is resistant and poorly compatible with cold spray, i.e., the powder deposition efficiency is low or zero; for example, a material with a hardness greater than or equal to 45 HRC is used to promote the rebound of powder particles on the plate. Preferably, the material constituting the plate 48 is a coated or uncoated metallic alloy.

[0110] Plate 48 may or may not have a textured surface, for example, with saw teeth or bevels. Plate 48 may be in the form of a clasp, negatively shaped to fit the shape of the paddle 9.

[0111] Preferably, the lower face 48.5 is in direct contact with the extrados 11.3 of the blade 9 and conforms to it, so as to ensure rigid and homogeneous support of the blade by the plate 48. The succession of pins 52 following the trajectory of the groove 40 makes it possible to effectively press the cable 32, 132 against the bottom 43 of said groove 40, in order to avoid the creation of air zones under the cable, prior to a first dynamic projection during the holding step 106 of the process 100 of figure 2.

[0112] Each stud 52 includes a lateral face 52.1 preferably having the same inclination as the flanks 41 of the groove 40, said face 52.1 being configured to come into contact and bear against the flank 41. This configuration has the advantage of increasing the bearing force towards the cable 32, 132 and thus ensuring its good contact with the bottom 43 of the groove 40. However, this can create a slot 51, so an optional tab 48.3 for protecting the slot 51 can protrude from the first plate to prevent the projection of metal powder directly onto the intrados 11.3 through the slot 51.

[0113] With reference to figure 9, the first plate of the device allowed, by means of the first projection (a first step 106 of cold spray) through the succession of orifices, to form a succession of anchoring bridges 42.1 extending to the right of the groove 40 at the level of each orifice 50 visible in figure 8.

[0114] Advantageously, each anchor bridge 42.1 locally forms at most 50% of the total volume of the groove to be filled, so as to allow total covering of the groove 40 by means of a second dynamic projection (a second cold spray stage 108) which will result in a total filling visible in figure 11.

[0115] With reference to process 100 of figure 2, the holding step 106 comprising holding the cable 32 in the groove 40 is advantageously ensured by the anchoring bridges 42.1 (after the first cold spray step), said holding step 106 optionally begins before the cold spray thanks to the cable clamping pins against the bottom of the groove 40.

[0116] An alternative to the metallic material sprayed during the first cold spray to form the anchoring brackets 42.1 can be resin injection. As an alternative or in addition to the anchoring brackets 42.1 and / or the retention by the pins in the retention step 106, various techniques can be used, for example: bonding; brazing; oversleeving; groove peening; welding; vacuum bagging; magnetizing the electrical conductor; using a wheel combined with the cold gas spraying tool, micro-welding, etc.

[0117] For example, a few points or a continuity of glue or solder (e.g., using solder paste) can be made to hold the cable in the groove, prior to the cold spray step.

[0118] In one variation, an oversleeve secures the cable sheath at the bottom of the groove. In another variation, the sides of the groove are locally deformed (plastically molded) to reduce the groove opening and prevent the cable from coming out.

[0119] Another possible technique involves swaging a wire over the 32 cable. The wire can be made of aluminum or nickel (or any other malleable / ductile material). The swaged wire holds the 32 cable at the bottom of the groove. Cold spraying then follows, with the wire embedded in the material along with the 32 cable.

[0120] Another example includes the use of a magnet, for example, at platform 46 of device 44 in Figure 8, with a paramagnetic cable sheath.

[0121] In other variations, shrink fitting can be used by cooling the cable and / or heating the component to modulate the cable cross-section (e.g., saturated cross-section) or the groove shape (e.g., teardrop or keyhole shape) to optimize the shrink fit. A vacuum could be created in the groove using holes located at its bottom, opening onto the upper surface of the blade. This approach would allow a tool to attract and hold the cable at the bottom of the groove using suction.

[0122] Other alternatives for securing the cable include laser microsoldering or soft soldering; or soldering via a ball capacitor (soldered microlink).

[0123] Finally, any combination of at least two of these techniques can be considered. Figure 10 shows an exploded and perspective view of the device 44 according to the invention, showing the blade 9 after partial covering of the cable 32; 132 by means of the anchoring brackets 42.1 (visible only in Figure 9).

[0124] We observe here a second plate 54 intended to replace the first plate 48 of figure 6, preferably by a manual change, just after the first cold spray step in the holding step 106, and before the second cold spray step in the covering step 108.

[0125] The second plate 54 includes a single orifice 154 which also extends along the path defined by the groove 40, and continuously over said second plate 54 over a total extent of said groove 40. Preferably, the material constituting the second plate 54 is similar to that of the first plate 48.

[0126] The second plate 54 is intended to be fixed against the receiving face 46.3 similarly to the first plate 48 to ensure the second cold spray stage, and thus completely cover the groove 40, as illustrated in figure 11.

[0127] With reference to figure 11, here the second cold spray is finished and the cable 32 is completely embedded in the groove thanks to a second layer of sprayed powder 42.1 which is superimposed directly on the sheath 38 of the cable 32 and on the succession of anchoring bridges 42.1, thus forming a metallic coating 42 which completely fills the groove of the blade 9, this is the result of the coating step 108 of the process 100 according to the invention.

[0128] Advantageously, little by little during the second cold spray, the 42.1 anchor loops become superfluous and are gradually filled.

[0129] The second projected layer 42.2 can be configured to be flush with the outer surface 11.3 or slightly overhang said surface in order to control the condition of said surface 11.3. Optional machining (polishing for example) may be required.

[0130] The metal cladding material 42 may be suitable for surface treatment of the blade, for example, anodizing to protect it against corrosion and erosion. The intended filling of the groove 40 is complete, meaning the blade is free of any cavities. The cable 32 and the metal cladding 42 may be the only two elements in the groove.

[0131] Cold spray ensures good adhesion of the metallic coating 42 to the blade, the said sprayed material 42 being compact and dense (with a porosity rate generally less than 1%), effectively maintaining and protecting the electrical conductor.

[0132] Advantageously, thanks to the two-stage cold spray process of the invention, the blade 9 has no void between the base 43 and the cable 32, and the entire volume of the groove is filled by the metallic coating 42. This ensures good heat transfer between the de-icing conductor and the outer surface 11.3 of the blade 11. The blade 9 according to the invention is therefore of better quality with guaranteed material integrity.

[0133] It should be noted that the invention was presented for the de-icing of a blade, but a person skilled in the art would adapt the same teachings to de-ice any other part of the turbomachine (shroud, casing, structural arms, flow separation nozzle, etc.), by depositing an electrical conductor and then covering it by projection with cold gas, said covering being able to be partial or total using the holding device according to the invention, for any other part of the turbomachine.

Claims

Demands 1. A method (100) for manufacturing a turbine blade (9) for a turbomachine (4), the method (100) comprising: - the manufacture (102) of a body by forging, casting, machining and / or additive manufacturing; and - the placement (104) of an electrical conductor (32) on the body; and - the coating (108) of the electrical conductor (32) by dynamic projection by cold gas of a metallic powder through at least one orifice (50; 150) of a plate (48; 54) disposed substantially parallel and opposite the electrical conductor (32; 132).

2. Method (100) according to claim 1, wherein the electrical conductor (32; 132) is completely covered by a second dynamic cold gas projection through a single orifice (150) of a second plate (54), said method further comprising holding (106) the electrical conductor (32; 132) on the body by means of a first dynamic cold gas projection of a metallic powder through a succession of orifices (50) of a first plate (48), prior to the total covering of the electrical conductor (32; 132) by the second projection.

3. Method (100) according to claim 2, wherein the first dynamic projection is through a succession of orifices (50) of the first plate (48), so as to form anchoring bridges (42.1) in projected metal powder fixing the electrical conductor (32; 132) on the blade body (9).

4. Method (100) according to claim 3, wherein the anchoring bridges (42.1) fix the electrical conductor (32; 132) against a bottom (43) of a path (40) of said electrical conductor (32; 132) formed in the body.

5. Method (100) according to claim 4, wherein the retention (106) of the electrical conductor (32; 132) on the body comprises a plating of said conductor (32; 132) by pins (52) extending from the first plate (48), prior to and during the first dynamic projection forming the anchoring bridges (42.1).

6. Method (100) according to any one of claims 1 to 5, wherein each of the succession of orifices (50) of the first plate (48) and of the orifice (150) of the second plate (150), extends along a trajectory defined by the path (40) on the blade (9).

7. Method (100) according to any one of claims 1 to 6, wherein the coating (108) is such that the metallic material (42) resulting from the dynamic cold gas projection of a metallic powder fills the path (40) to be flush with an outer surface (11.3, 11.4) of the blade (9).

8. Method (100) according to any one of claims 1 to 7, wherein the blade (9) is held by a corresponding fixing platform (46), and the plate (48; 54) is disposed on a receiving face (46.3) of the platform (46).

9. Method (100) according to claims 2 and 8, wherein said method (100) comprises a change of the first plate (48) by the second plate (54) on the platform (46), between the first projection and the second projection.

10. Method (100) according to any one of claims 1 to 9 and according to claim 2, wherein the retention (106) of the electrical conductor (32; 132) on the body is ensured by at least one of the following means: gluing; brazing; oversleeving; fitting of bridges; peening of the body; peening of the electrical conductor (32; 132); vacuum packing; magnetizing of the electrical conductor (32; 132); shrink fitting; use of a wheel combined with the cold gas spraying tool; microwelding.

11. Method (100) according to any one of claims 2 to 10, wherein the retention (106) of the electrical conductor (32; 132) on the body and the covering (108) of said electrical conductor (32; 132) are ensured by means of a device (44) according to any one of claims 11 to 22.

12. Device (44) for holding a substrate (9) for dynamic cold gas projection of a metallic powder onto said substrate (9), characterized in that said device (44) comprises a substrate (9) mounting platform (46), such as a turbomachine blade (9), and at least one plate (48; 54) for mounting on said platform (46) to extend substantially parallel to an outer surface (11.3, 11.4) of said substrate (9), the at least one plate (48; 54) comprising at least one orifice (50; 150) configured to be disposed opposite a path (40) opening onto said outer surface (11.3, 11.4) and comprising an electrical conductor (32; 132), said at least one orifice (50; 150) being configured to allow the passage of a metal powder projected by dynamic cold gas spraying towards said path (40), so as to at least partially cover the electrical conductor (32; 132), said device (44) being adapted to a method (100) according to one of the claims 1 to 11.

13. Device (44) according to claim 12, wherein at least one orifice (50; 150) extends along a trajectory defined by the path (40) on the substrate (9).

14. Device (44) according to any one of claims 12 and 13, wherein at least one plate (48; 54) comprises a first plate (48) and a second plate (54) configured for sequential use with said platform (46).

15. Device (44) according to claims 13 and 14, wherein the first plate (48) forms a succession of orifices (50) which follow the path of the path (40), so that the metallic powder projected through said succession of orifices (50) forms a succession of anchoring bridges (42.1) capable of holding the electrical conductor (32; 132) against a bottom (43) of the path (40).

16. Device (44) according to claim 15, wherein the first plate (48) comprises studs (52) made of material with said first plate (48), said studs (52) being configured to extend in the path (40) so as to press the electrical conductor (32; 132) against the bottom (43) of said path (40).

17. Device (44) according to claim 16, in which each pin (52) is formed between two adjacent orifices (50) of the succession of orifices (50).

18. Device (44) according to any one of claims 15 to 17, wherein each orifice (50) of the succession of orifices (50) is distant from an adjacent orifice (50) by a distance (d) corresponding to at most twice the average of an extent (e) of each of said orifices (50).

19. Device (44) according to any one of claims 15 to 18, wherein the succession of orifices (50) extends at regular intervals along a whole extent of the path (40) on the substrate (9).

20. Device (44) according to any one of claims 14 to 19, wherein the second plate (54) has a single orifice (150) which follows a trajectory defined by the path (40) on the substrate (9), said orifice (150) extending continuously over said second plate (54) along a total extent of said path (40) on the substrate (9).

21. Device (44) according to any one of claims 12 to 20, wherein at least one plate (48, 54) is configured to be mounted on the platform (46) by means of threaded guide pins (45) projecting from a receiving face (46.3) of said platform (46), and wing nuts (49) intended to clamp at least one plate (48, 54) by an engagement of said nuts (49) with the threaded guide pins (45).

22. Device (44) according to claims 14 and 21, wherein the first plate (48) is split into two parts (48.1, 48.2) configured to come together on the receiving face (46.3) and constitute said first plate (48).

23. Device (44) according to any one of claims 12 to 22, wherein the substrate (9) corresponds to a turbomachine blade (9), and the outer surface (11.3, 11.4) being the intrados (11.3) or the extrados (11.4) of said blade.

24. Turbomachine blade (9) (4) comprising an electrical conductor (32; 132), characterized in that said blade (9) is obtained by process (100) manufacturing a turbine blade (9) according to any one of claims 1 to 11.

25. Blade (9) according to claim 24, characterized in that the electrical conductor (32; 132) comprises at least one electrical line (34) encased in an insulating sheath (38).

26. Compressor (2) of turbomachine (4) comprising a blade (9), the compressor (2) being characterized in that the blade (9) is according to one of claims 23 and 24, or is manufactured at least partially by the process (100) according to one of claims 1 to 11.

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