EP4021663A1 - Improved method for manufacturing a ceramic core for manufacturing turbomachine vanes - Google Patents

Improved method for manufacturing a ceramic core for manufacturing turbomachine vanes

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Publication number
EP4021663A1
EP4021663A1 EP20775042.3A EP20775042A EP4021663A1 EP 4021663 A1 EP4021663 A1 EP 4021663A1 EP 20775042 A EP20775042 A EP 20775042A EP 4021663 A1 EP4021663 A1 EP 4021663A1
Authority
EP
European Patent Office
Prior art keywords
orifice
ceramic
core
manufacturing
blank
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP20775042.3A
Other languages
German (de)
French (fr)
Other versions
EP4021663B1 (en
Inventor
Adrien Bernard Vincent ROLLINGER
Alice Marie Lydie AGIER
Gaël Philippe François BATTISTONI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Safran SA
Original Assignee
Safran SA
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Filing date
Publication date
Application filed by Safran SA filed Critical Safran SA
Publication of EP4021663A1 publication Critical patent/EP4021663A1/en
Application granted granted Critical
Publication of EP4021663B1 publication Critical patent/EP4021663B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C9/00—Moulds or cores; Moulding processes
    • B22C9/10—Cores; Manufacture or installation of cores
    • B22C9/103—Multipart cores
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C21/00—Flasks; Accessories therefor
    • B22C21/12—Accessories
    • B22C21/14—Accessories for reinforcing or securing moulding materials or cores, e.g. gaggers, chaplets, pins, bars
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22C—FOUNDRY MOULDING
    • B22C7/00—Patterns; Manufacture thereof so far as not provided for in other classes
    • B22C7/02—Lost patterns

Definitions

  • This presentation relates to the field of the manufacture of turbomachine blades according to the lost wax casting technique, in particular the manufacture of ceramic cores used for the manufacture of these blades according to this technique.
  • the present disclosure relates to a method of manufacturing such a ceramic core, intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique.
  • the blades present in the turbomachines in particular the turbine blades, for example low pressure, generally include internal cavities necessary for cooling these blades.
  • these cavities are formed, before the formation of the wax mold, by means of ceramic cores, the shape of which corresponds to the desired shape of the cavities in the final piece.
  • a portion of such a core 10 is shown schematically in FIG. 1.
  • These ceramic cores generally comprise a first part 20, the first part 20 being a functional part corresponding to the future cavities of the blade and having the shape thereof. (only the upper end of the first part, corresponding to the top, or head of the blade, is visible in FIG.
  • the second part 30 also comprises a functional portion, at its lower end, serving in particular to form the contour of the tub of the vane at the end of the manufacturing process thereof. So that the metal can be poured around the core, in particular around the upper portion of the first part 20 of the core 10 visible in Figure 1, to form the cavities of the blade, the first part 20 must be spaced of the second part 30, while being integral with the latter and maintained by the latter.
  • thin rods 40 are arranged between these two parts, and keep these parts integral with one another and fixed with respect to each other, while leaving a space S between these two parts.
  • the cast metal entering this space S between these two parts will correspond to the bottom wall of the top tub of the vane, at the end of the manufacturing process of the vane.
  • the rods 40 are directly placed in a mold and a ceramic paste is injected around.
  • suitable manufacturing techniques such as additive manufacturing.
  • This technique in which the core is built layer by layer, does not allow the insertion of the rods during manufacture. It is therefore necessary to provide orifices in the core during the additive manufacturing of the latter, in order to be able to insert the rods therein a posteriori.
  • the insertion of these rods first requires cleaning, that is to say emptying the holes provided for this purpose, of the excess ceramic material that settles there during the printing of the core.
  • the present disclosure relates to a method of manufacturing a blank of a ceramic core intended for the manufacture of hollow turbomachine blades according to the foundry technique. with lost wax, the blank being manufactured by additive manufacturing and comprising:
  • junction portion is formed at the same time as the first part and the second part during additive manufacturing, and therefore comprises the same material as these parts.
  • the junction portion can be a 3D printed fabrication device, called a "printing medium", forming a junction portion between these two parts during printing.
  • the junction portion keeps these two parts integral with one another and fixed relative to each other temporarily, before insertion of the rods.
  • the contact between the junction portion and the first and second parts can be discontinuous.
  • the junction portion may include a plurality of pads or pins interposed between these two parts. This configuration makes it possible to facilitate the subsequent removal of this junction portion, after the positioning of the positioning rods.
  • blade it is understood that this is an intermediate state of the core during its manufacture, in particular before the insertion of the rods.
  • the manufacture of the blank by additive manufacturing is carried out such that the blank thus obtained comprises the first part, the second part, and the junction portion.
  • this manufacture provides for the presence of at least one through hole.
  • through or “through”, it is understood that the orifice opens out on either side of the blank, as opposed to a blind hole comprising a bottom.
  • the orifice passes through the second part, the junction portion and the first part, opening at each of its ends into a region outside the blank of the core, around the latter.
  • the cleaning removes these residues, in order to allow the insertion of the positioning rod.
  • the configuration of the present disclosure makes it possible to easily expel these residues through one emerging end of the orifice, by applying pressure, for example by injecting a mixture of solvent and pulsed air, at the other emerging end of the orifice. 'orifice. It is thus possible to carry out the cleaning of the orifice efficiently, by dispensing with the use of unsuitable tools such as drills, thus limiting the waste rate of the cores.
  • the junction portion comprises a passage placing the through-orifice in fluid communication with a space external to the core blank.
  • This passage makes it easier to clean the through hole. Indeed, when the cleaning of the orifice is carried out by injecting a solvent, for example, at both ends of the orifice, the residues of ceramic paste dissolved in the solvent can be discharged through this passage.
  • the through orifice comprises a first rectilinear portion extending from the first end, and a second rectilinear portion having an angle of less than 180 ° relative to the first rectilinear portion, and extending from the second end.
  • the first rectilinear portion extends through the second part from the first end to the junction portion, through the junction portion and a part of the first part.
  • the second rectilinear portion extends in the first part between the end of the first portion rectilinear located in the first part, and the second end.
  • the first rectilinear portion and the second rectilinear portion form between them an elbow having an angle of less than 180 °, this elbow preferably being placed in the first part.
  • the length of the first straight portion can be determined depending on the length of the positioning rod to be inserted. The presence of this bend makes it possible to shorten the length of the second rectilinear portion of the orifice, and in particular makes it possible to reach the outside of the core.
  • the angle between the first and the second rectilinear portion is greater than or equal to 100 °, preferably between 110 ° and 120 °.
  • the diameter of the first rectilinear portion of the through hole is between 0.15 and 0.3 mm.
  • the diameter of the first rectilinear portion can be determined as a function of the diameter of the positioning rod to be inserted. Preferably, there should be clearance between the positioning rod and the orifice.
  • the diameter of the second rectilinear portion of the through-hole is between 0.4 and 0.6 mm.
  • the through orifice may have a circular section. These values make it easier to insert the positioning rods and clean the holes. In fact, diameters that are too large would not be suitable for cleaning techniques such as the injection of pulsed air and / or solvent, and would make this injection ineffective. The operation of filling the orifices would also be longer, more complex, and would require a large quantity of ceramic paste to fill these orifices. In addition, too large diameters would adversely affect the mechanical properties of the core and would not allow precise positioning of the positioning rods. Conversely, diameters that are too small would prevent the insertion of the positioning rods.
  • This disclosure also relates to a method of manufacturing a ceramic core intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique, the method comprising a step of manufacturing a blank by the method according to any one of the preceding embodiments, and also comprising, after the manufacture of the blank:
  • non-solidified residues of ceramic paste remain in the orifice. Cleaning removes these residues to allow insertion of the positioning rod. Furthermore, the elimination of the junction portion can be carried out by sintering the ceramic using a suitable tool, for example a high precision grinding wheel making it possible to free the space between the first part and the second part. .
  • the cleaning of the through orifice is achieved by injecting pulsed air and / or a solvent into at least one end of the orifice.
  • Pulsed air alone, a solvent alone, or a mixture of the two can be used for cleaning the orifice.
  • the forced air and / or the solvent injected at one end of the orifice is evacuated, carrying the ceramic paste residues, through the other end of the orifice and / or through the passage in the portion of junction.
  • the pulsed air and / or the solvent injected at both ends of the orifice, simultaneously or not, is evacuated, carrying the ceramic paste residues, through the passage in the junction portion.
  • This technique also has the advantage of being fast, and does not add an additional step, unlike the use of a drill to clean the orifices according to the prior art.
  • the cleaning of the orifices by forced air and / or solvent can be carried out at the same time as the cleaning of the core.
  • the cleaning of the through hole is achieved by mechanically inserting a cleaning means into at least one end of the hole.
  • This technique of mechanical insertion of a cleaning means can be carried out alone, or in addition to the forced air and / or the solvent.
  • the cleaning step and the insertion step are performed simultaneously.
  • the fact of inserting the rod at one end of the through hole pushes the ceramic residue, which residue can escape through the other end of the hole.
  • the rod itself thus acts as a means of mechanical cleaning.
  • the positioning rods are alumina rods.
  • Alumina rods are a ceramic material having the advantage of being resistant to the same thermal stresses as the rest of the part and having the same chemical properties on release. They also allow great tensile / compressive strength to ensure dimensional stability of the bottom thickness of the tub, as well as a solid grip between the first and second part.
  • rods comprising molybdenum can be used.
  • the filling of the through orifice is carried out by applying a ceramic paste to both ends of said orifice.
  • the method comprises, after filling, a hardening step making it possible to harden the ceramic paste.
  • the curing step comprises, for example, exposure under a UV lamp makes it possible to harden the ceramic paste used for the filling. This improves the overall rigidity of the ceramic core, when fabrication is complete.
  • the positioning rods are coated with ceramic glue.
  • This disclosure also relates to a ceramic core blank intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique, and comprising:
  • This disclosure also relates to a use of a ceramic core obtained by the method according to any one of the embodiments of the present disclosure, for the manufacture of hollow turbine blade of a turbomachine according to the technique of the foundry in lost wax.
  • Figure 1 shows schematically a plan view of a portion of a ceramic core intended to be used for the manufacture of turbomachine hollow blades according to the lost wax casting technique
  • FIG. 2A-2B Figure 2A schematically shows a technique for cleaning an orifice according to the prior art, and Figure 2B schematically shows a technique for cleaning an orifice according to the present disclosure
  • Figure 3 shows a schematic view in transparency of a portion of a ceramic core of the present disclosure
  • Fig. 4 is a diagram showing the manufacturing process of a ceramic core according to the present disclosure.
  • Figures 2A and 2B schematically show samples of a ceramic core, in the form of test pieces, illustrating the cleaning of an orifice of this core.
  • Figure 2A schematically shows a technique for cleaning an orifice 50 according to the prior art.
  • the orifice 50 is blind.
  • the hatched part represents the ceramic core, more precisely, the polymerized paste forming the ceramic core.
  • the latter comprises a first part 20, a second part 30, and a junction portion 60.
  • the shaded part represents the unpolymerized ceramic paste remaining in the orifice 50 after the printing of the core blank.
  • the core blank is produced layer by layer, starting with the first part 20 for example, then the junction portion 60, then the second part 30, by providing for the presence of the one or more orifices 50.
  • the junction portion 60 has a serrated shape, limiting the contact surface between the junction portion 60 and the first part 20 and / or the second part 30.
  • the junction portion 60 can thus comprise a plurality of teeth 61 , in the form of pins or studs, interposed between these two parts.
  • the orifice 50 is non-opening and comprises a bottom 51.
  • the operation of cleaning the orifice is carried out, for example, by means of a drill 70, the passage of which through the orifice 50 allows the dough to be evacuated. Such a technique causes deterioration or breakage of many ceramic cores.
  • Figure 2B schematically shows a technique for cleaning an orifice 50 according to the present disclosure.
  • the orifice 50 is through. More specifically, the orifice 50 comprises a first rectilinear portion 50a extending through the second part 30, the junction portion 60 and the first part 20, and a second rectilinear portion 50b extending through the first part 20 from the end of the first rectilinear portion 50a, and opening onto an external face of the first part 20.
  • the first rectilinear portion 50a is preferably longer than the second rectilinear portion 50b, and is intended to receive a positioning rod.
  • the angle b between the first and the second rectilinear portion 50a, 50b is less than 180 °, and greater than or equal to 100 °, preferably between 110 ° and 120 °.
  • a passage 62 is provided in the junction portion 60.
  • This passage 62 can be an orifice, or a local absence of teeth 61, making it possible to put the orifice 50 in fluid communication with a region external to the ceramic core, and surrounding it.
  • This passage 62 makes it possible to facilitate the operation of cleaning the orifice 50.
  • the cleaning of the orifice 50 can be carried out by injecting pulsed air into one. or at both ends of the orifice 50.
  • the pressure exerted at the ends of the orifice 50 allows the discharge of the unpolymerized paste present in the orifice, through the passage 62 of the junction portion 60 (see arrows on Figure 2A).
  • a solvent can be injected, or a mixture of air and solvent.
  • a cylindrical tool of suitable diameter can be used to push the paste, in addition to or in place of air and / or solvent.
  • Figure 3 shows a schematic view of part of a ceramic core 10 according to the present disclosure, produced by additive manufacturing, comprising a first part 20, a second part 30, and a junction portion 60.
  • the first part 20 shows the shape of the cavities you want get at the end of manufacturing the turbine blade. In FIG. 3, only the upper end of the first part 20, corresponding to the upper end, or top, of the blade, is visible.
  • the second part 30, or dome allows the maintenance of the ceramic core 10 during the production of the wax model, and during the casting of the metal in a ceramic shell mold.
  • the first part 20 and the second part 30 are spaced from each other by a distance S of between 0.4 and 1.4 mm.
  • three through orifices 50 extend through the second part 30, the junction portion 60 and the first part 20.
  • Each of these orifices 50 comprises a first rectilinear portion 50a opening onto an outer face of the second part 30, and a second rectilinear portion 50b (only one of which is visible in FIG. 3) opening out an external face of the first part 20.
  • a positioning rod 40 is inserted into each of these orifices 50.
  • These positioning rods 40 may be alumina rods, and may have a length of 13 mm and a diameter of 0.6 mm. However, these dimensions are not limiting, and can be modified according to the geometry considered of the core.
  • a first step in the manufacture of a ceramic core 10 comprises the manufacture of a blank of the core by additive manufacturing (step S1).
  • the blank comprises the first part 20, the junction portion 60 and the second part 30.
  • Additive manufacturing provides for the presence of the through holes 50, and of the passage (s) 62 in the junction portion 60.
  • the orifices 50 are cleaned, that is to say emptied of the residues of unpolymerized ceramic paste remaining in the orifices 50 (step S2).
  • forced air and / or solvent for example For example, is injected at the ends of the orifices 50.
  • the residual paste is thus discharged through the passage 62 of the junction portion 60.
  • a positioning rod 40 is then inserted into each through hole 50 (step S3). More precisely, a positioning rod 40 is inserted into the first rectilinear portion 50a of each through hole.
  • the rods 40 are inserted from the top, that is to say through the end of the orifice 50 opening onto an external face of the second part 30, and pressed into the orifice 50 so as to extend to both in the second part 30 and in the first part 20.
  • the rods 40 can be coated beforehand with ceramic glue. This adhesive solidifies during the heat treatment described below, and allows optimal coating of the rod.
  • step S4 After the positioning of the positioning rods 40 in the orifices 50, the latter are plugged (step S4).
  • This filling is carried out using a ceramic paste, so as to obtain a smooth surface condition, on the external faces of the first and second parts 20 and 30. This makes it possible to avoid surface irregularities subsequently on the model. in wax, and on the final piece.
  • the filling is followed by a step of hardening the ceramic paste, making it possible to solidify the paste added in step S4 (step S5).
  • This step can be carried out depending on the properties of the paste, depending on whether it is, for example, photosensitive or heat-sensitive, in particular by means of a UV light source or a heat source.
  • the curing step is performed by exposure to UV light.
  • the core 10 can also follow a heat treatment step, comprising debinding and sintering.
  • the method finally comprises the elimination of the junction portion 60 (step S6).
  • This elimination is facilitated by the serrated shape of the junction part 60, and can be achieved by any suitable tool, which can be inserted between the first part and the second part.
  • the first part 20 and the second part 30 are held together, and positioned with respect to each other, by the positioning rods 40 only.
  • the ceramic core 10 thus obtained can then be used in the manufacture of hollow turbomachine blades according to the lost wax casting technique.
  • the ceramic core 10 can be placed in a wax mold, being held by the second part 30, to form the wax model having the shape of the final part, with the cavities formed by the first part 20 of the core.
  • the wax model is then dipped several times in a slip to form the ceramic mold.
  • the molten metal is poured into the ceramic mold and around the ceramic core, the latter being again held in a fixed position by means of the second part 30. Finally, the ceramic mold and the ceramic core 10 are then eliminated, for example by unhooking, in order to obtain the final part.
  • the removal of the ceramic also includes the removal of the positioning alumina rods 40, removed during the unhooking, then leaving small holes through the tub at the top of the vane, where it sits. were finding these rods. These orifices serve in particular as dust removal or evacuation holes for the air present in the cavities of the vane.

Abstract

Method for manufacturing a blank for a ceramic core (10) for the manufacture of hollow turbomachine vanes according to the lost-wax casting technique, the blank being manufactured by additive manufacture and comprising at least a first portion (20) which is intended to form the cavities of the hollow vanes and at least a second portion (30) which is configured to allow the core (10) to be positioned in a wax mould, the second portion (30) and the first portion (20) being positioned and retained relative to each other by means of a joint portion (60) which is interposed between the first portion (20) and the second portion (30), at least one through-hole (50) extending through the second portion (30), the joint portion (60) and the first portion (20), a first end of the through-hole (50) opening at an outer face of the second portion (30), and a second end of the through-hole (50) opening at an outer face of the first portion (20).

Description

Description Description
Titre de l'invention : Procédé amélioré de fabrication d'un noyau céramique pour la fabrication d'aubes de turbomachine Title of the invention: Improved method of manufacturing a ceramic core for manufacturing turbomachine blades
Domaine Technique Technical area
[0001 ] Le présent exposé concerne le domaine de la fabrication des aubes de turbomachine selon la technique de la fonderie à la cire perdue, notamment la fabrication des noyaux céramiques utilisés pour la fabrication de ces aubes selon cette technique. En particulier, le présent exposé concerne un procédé de fabrication d’un tel noyau céramique, destiné à la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue. This presentation relates to the field of the manufacture of turbomachine blades according to the lost wax casting technique, in particular the manufacture of ceramic cores used for the manufacture of these blades according to this technique. In particular, the present disclosure relates to a method of manufacturing such a ceramic core, intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique.
Technique antérieure Prior art
[0002] Les aubes présentes dans les turbomachines, notamment les aubes de turbine, par exemple basse pression, comportent généralement des cavités internes nécessaires au refroidissement de ces aubes. Lors de la fabrication des aubes selon la technique de la fonderie à la cire perdue, ces cavités sont formées, avant la formation du moule en cire, par l’intermédiaire de noyaux en céramique, dont la forme correspond à la forme souhaitée des cavités dans la pièce finale. Une portion d’un tel noyau 10 est représentée schématiquement sur la figure 1. Ces noyaux céramiques comprennent généralement une première partie 20, la première partie 20 étant une partie fonctionnelle correspondant aux futures cavités de l’aube et ayant la forme de celles-ci (seule l’extrémité supérieure de la première partie, correspondant au sommet, ou tête de l’aube, est visible sur la figure 1), et une deuxième partie 30, appelée par exemple dôme, servant de région de maintien du noyau 10. Plus précisément, lors de la coulée de la cire autour du noyau 10, ou l’évacuation de la cire, le noyau 10 est maintenu en position fixe par rapport au moule céramique par l’intermédiaire d’une portion non fonctionnelle de cette deuxième partie 30. La deuxième partie 30 comprend également une portion fonctionnelle, au niveau de son extrémité inférieure, servant notamment à former le contour de la baignoire de l’aube à la fin du processus de fabrication de celle-ci. [0003] Pour que le métal puisse être coulé autour du noyau, notamment autour de la portion supérieure de la première partie 20 du noyau 10 visible sur la figure 1 , pour former les cavités de l’aube, la première partie 20 doit être espacée de la deuxième partie 30, tout en étant solidaire de cette dernière et maintenue par cette dernière. Pour ce faire, de fines tiges 40 sont disposées entre ces deux parties, et maintiennent ces parties solidaires l’une de l’autre et fixes l’une par rapport à l’autre, tout en laissant un espace S entre ces deux parties. Ainsi, le métal coulé pénétrant dans cet espace S entre ces deux parties correspondra à la paroi de fond de la baignoire de sommet de l’aube, à la fin du processus de fabrication de l’aube. The blades present in the turbomachines, in particular the turbine blades, for example low pressure, generally include internal cavities necessary for cooling these blades. During the manufacture of the blades according to the technique of the lost wax casting, these cavities are formed, before the formation of the wax mold, by means of ceramic cores, the shape of which corresponds to the desired shape of the cavities in the final piece. A portion of such a core 10 is shown schematically in FIG. 1. These ceramic cores generally comprise a first part 20, the first part 20 being a functional part corresponding to the future cavities of the blade and having the shape thereof. (only the upper end of the first part, corresponding to the top, or head of the blade, is visible in FIG. 1), and a second part 30, called for example a dome, serving as a retaining region for the core 10. More precisely, during the casting of the wax around the core 10, or the evacuation of the wax, the core 10 is maintained in a fixed position relative to the ceramic mold by means of a non-functional portion of this second part 30. The second part 30 also comprises a functional portion, at its lower end, serving in particular to form the contour of the tub of the vane at the end of the manufacturing process thereof. So that the metal can be poured around the core, in particular around the upper portion of the first part 20 of the core 10 visible in Figure 1, to form the cavities of the blade, the first part 20 must be spaced of the second part 30, while being integral with the latter and maintained by the latter. To do this, thin rods 40 are arranged between these two parts, and keep these parts integral with one another and fixed with respect to each other, while leaving a space S between these two parts. Thus, the cast metal entering this space S between these two parts will correspond to the bottom wall of the top tub of the vane, at the end of the manufacturing process of the vane.
[0004] Dans les techniques d’injection classiques, les tiges 40 sont directement placées dans un moule et une pâte céramique est injectée autour. Cependant, la complexité de certains noyaux céramiques nécessite des techniques adaptées de fabrication, telles que la fabrication additive. Cette technique, dans laquelle le noyau est construit couche par couche, ne permet pas l’insertion des tiges pendant la fabrication. Il est donc nécessaire de prévoir des orifices dans le noyau lors de la fabrication additive de ce dernier, afin de pouvoir y insérer les tiges a posteriori. Néanmoins, l’insertion de ces tiges nécessite d’abord de nettoyer, c’est-à-dire vider les trous prévus à cet effet, de l’excédent de matière céramique qui s’y dépose pendant l’impression du noyau. [0004] In conventional injection techniques, the rods 40 are directly placed in a mold and a ceramic paste is injected around. However, the complexity of some ceramic cores requires suitable manufacturing techniques, such as additive manufacturing. This technique, in which the core is built layer by layer, does not allow the insertion of the rods during manufacture. It is therefore necessary to provide orifices in the core during the additive manufacturing of the latter, in order to be able to insert the rods therein a posteriori. However, the insertion of these rods first requires cleaning, that is to say emptying the holes provided for this purpose, of the excess ceramic material that settles there during the printing of the core.
[0005] Cependant, le vidage de ces orifices est complexe du fait du petit diamètre et de la longueur importante de ces derniers. Cette étape de nettoyage des orifices mène de plus à des détériorations fréquentes des noyaux, et à de nombreux rebuts de ces noyaux. Les outils et les techniques actuels ne permettent pas de réaliser cette opération de manière efficace. However, emptying these orifices is complex due to the small diameter and the large length of the latter. This step of cleaning the orifices also leads to frequent damage to the cores, and to numerous rejects of these cores. Current tools and techniques do not allow this operation to be carried out efficiently.
Exposé de l'invention Disclosure of the invention
[0006] Afin de pallier au moins en partie aux inconvénients mentionnés ci- dessus, le présent exposé concerne un procédé de fabrication d’une ébauche d’un noyau céramique destiné à la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, l’ébauche étant fabriquée par fabrication additive et comprenant : [0006] In order to at least partially alleviate the drawbacks mentioned above, the present disclosure relates to a method of manufacturing a blank of a ceramic core intended for the manufacture of hollow turbomachine blades according to the foundry technique. with lost wax, the blank being manufactured by additive manufacturing and comprising:
- au moins une première partie destinée à former les cavités des aubes creuses, - au moins une deuxième partie configurée pour permettre le positionnement du noyau dans un moule à cire, la deuxième partie et la première partie étant positionnées et maintenues l’une par rapport à l’autre par l’intermédiaire d’une portion de jonction intercalée entre la première partie et la deuxième partie,- at least a first part intended to form the cavities of the hollow blades, - at least a second part configured to allow the positioning of the core in a wax mold, the second part and the first part being positioned and held relative to each other by means of an interposed junction portion between the first part and the second part,
- au moins un orifice traversant s’étendant à travers la deuxième partie, la portion de jonction et la première partie, une première extrémité de l’orifice traversant débouchant sur une face externe de la deuxième partie, et une deuxième extrémité de l’orifice traversant débouchant sur une face externe de la première partie. - at least one through orifice extending through the second part, the junction portion and the first part, a first end of the through orifice opening onto an external face of the second part, and a second end of the orifice crossing opening onto an external face of the first part.
[0007] On comprend que la portion de jonction est formée en même temps que la première partie et la deuxième partie au cours de la fabrication additive, et comprend donc le même matériau que ces parties. La portion de jonction peut être un artifice de fabrication imprimé en 3D, appelé « support d’impression », formant une portion de jonction entre ces deux parties pendant l’impression. En particulier, la portion de jonction permet de maintenir ces deux parties solidaires l’une de l’autre et fixes l’une par rapport à l’autre de manière temporaire, avant l’insertion des tiges. Le contact entre la portion de jonction et les première et deuxième parties peut être discontinu. Par exemple, la portion de jonction peut comporter une pluralité de plots ou de picots intercalés entre ces deux parties. Cette configuration permet de faciliter le retrait ultérieur de cette portion de jonction, après la mise en place des tiges de positionnement. It is understood that the junction portion is formed at the same time as the first part and the second part during additive manufacturing, and therefore comprises the same material as these parts. The junction portion can be a 3D printed fabrication device, called a "printing medium", forming a junction portion between these two parts during printing. In particular, the junction portion keeps these two parts integral with one another and fixed relative to each other temporarily, before insertion of the rods. The contact between the junction portion and the first and second parts can be discontinuous. For example, the junction portion may include a plurality of pads or pins interposed between these two parts. This configuration makes it possible to facilitate the subsequent removal of this junction portion, after the positioning of the positioning rods.
[0008] Par « ébauche », on comprend qu’il s’agit d’un état intermédiaire du noyau au cours de sa fabrication, notamment avant l’insertion des tiges. La fabrication de l’ébauche par fabrication additive est réalisée de telle sorte que l’ébauche ainsi obtenue comprenne la première partie, la deuxième partie, et la portion de jonction. En outre, cette fabrication prévoit la présence d’au moins un orifice traversant. Par « traversant », ou « débouchant », on comprend que l’orifice débouche de part et d’autre de l’ébauche, par opposition à un trou borgne comprenant un fond. En particulier, l’orifice traverse la deuxième partie, la portion de jonction et la première partie, en débouchant à chacune de ses extrémités sur une région extérieure à l’ébauche du noyau, autour de ce dernier. [0008] By "blank", it is understood that this is an intermediate state of the core during its manufacture, in particular before the insertion of the rods. The manufacture of the blank by additive manufacturing is carried out such that the blank thus obtained comprises the first part, the second part, and the junction portion. In addition, this manufacture provides for the presence of at least one through hole. By "through" or "through", it is understood that the orifice opens out on either side of the blank, as opposed to a blind hole comprising a bottom. In particular, the orifice passes through the second part, the junction portion and the first part, opening at each of its ends into a region outside the blank of the core, around the latter.
[0009] Cette configuration permet de faciliter le nettoyage de l’orifice traversant. En effet, à la fin de la fabrication de l’ébauche par fabrication additive, des résidus non solidifiés de pâte céramique restent dans l’orifice, en raison notamment de la viscosité importante de cette pâte. This configuration makes it possible to facilitate the cleaning of the through orifice. Indeed, at the end of the manufacturing of the blank by additive manufacturing, Non-solidified residues of ceramic paste remain in the orifice, in particular because of the high viscosity of this paste.
[0010] Le nettoyage permet d’enlever ces résidus, afin de permettre l’insertion de la tige de positionnement. Or, la configuration du présent exposé permet d’expulser facilement ces résidus par une extrémité débouchante de l’orifice, en appliquant une pression, par exemple en injectant un mélange de solvant et d’air pulsé, à l’autre extrémité débouchante de l’orifice. Il est ainsi possible de réaliser efficacement le nettoyage de l’orifice, en s’affranchissant de l’utilisation d’outils non adaptés tels que des forets, limitant ainsi le taux de rebuts des noyaux. [0010] The cleaning removes these residues, in order to allow the insertion of the positioning rod. However, the configuration of the present disclosure makes it possible to easily expel these residues through one emerging end of the orifice, by applying pressure, for example by injecting a mixture of solvent and pulsed air, at the other emerging end of the orifice. 'orifice. It is thus possible to carry out the cleaning of the orifice efficiently, by dispensing with the use of unsuitable tools such as drills, thus limiting the waste rate of the cores.
[0011] Par ailleurs, selon l’art antérieur, la portion de l’orifice traversant la deuxième partie présentant une longueur importante, la longueur des forets ne permettaient pas de déboucher/nettoyer cette portion de l’orifice en une seule étape. Il était alors nécessaire d’imprimer cette deuxième partie en deux parties, afin de nettoyer l’orifice en deux étapes, puis de recoller les deux parties ensemble. La présence d’un orifice traversant selon le présent exposé permet de s’affranchir de cet inconvénient, simplifiant ainsi le processus de fabrication du noyau. [0011] Furthermore, according to the prior art, the portion of the orifice passing through the second part having a significant length, the length of the drills did not allow this portion of the orifice to be unblocked / cleaned in a single step. It was then necessary to print this second part in two parts, in order to clean the orifice in two stages, then to glue the two parts back together. The presence of a through orifice according to the present disclosure overcomes this drawback, thus simplifying the core manufacturing process.
[0012] Dans certains modes de réalisation, la portion de jonction comprend un passage mettant en communication fluidique l’orifice traversant et un espace extérieur à l’ébauche de noyau. [0012] In certain embodiments, the junction portion comprises a passage placing the through-orifice in fluid communication with a space external to the core blank.
[0013] Ce passage permet de faciliter le nettoyage de l’orifice traversant. En effet, lorsque le nettoyage de l’orifice est effectué en injectant un solvant, par exemple, aux deux extrémités de l’orifice, les résidus de pâte céramique dissouts dans le solvant peuvent être évacués par ce passage. [0013] This passage makes it easier to clean the through hole. Indeed, when the cleaning of the orifice is carried out by injecting a solvent, for example, at both ends of the orifice, the residues of ceramic paste dissolved in the solvent can be discharged through this passage.
[0014] Dans certains modes de réalisation, l’orifice traversant comprend une première portion rectiligne s’étendant depuis la première extrémité, et une deuxième portion rectiligne présentant un angle inférieur à 180° par rapport à la première portion rectiligne, et s’étendant depuis la deuxième extrémité. In some embodiments, the through orifice comprises a first rectilinear portion extending from the first end, and a second rectilinear portion having an angle of less than 180 ° relative to the first rectilinear portion, and extending from the second end.
[0015] De préférence, la première portion rectiligne s’étend à travers la deuxième partie depuis la première extrémité jusqu’à la portion de jonction, à travers la portion de jonction et une partie de la première partie. La deuxième portion rectiligne s’étend dans la première partie entre l’extrémité de la première portion rectiligne située dans la première partie, et la deuxième extrémité. En d’autres termes, la première portion rectiligne et la deuxième portion rectiligne forment entre elles un coude présentant un angle inférieur à 180°, ce coude étant de préférence disposé dans la première partie. La longueur de la première portion rectiligne peut être déterminée en fonction de la longueur de la tige de positionnement devant être insérée. La présence de ce coude permet de raccourcir la longueur de la deuxième portion rectiligne de l’orifice, et permet notamment d’atteindre l’extérieur du noyau. Preferably, the first rectilinear portion extends through the second part from the first end to the junction portion, through the junction portion and a part of the first part. The second rectilinear portion extends in the first part between the end of the first portion rectilinear located in the first part, and the second end. In other words, the first rectilinear portion and the second rectilinear portion form between them an elbow having an angle of less than 180 °, this elbow preferably being placed in the first part. The length of the first straight portion can be determined depending on the length of the positioning rod to be inserted. The presence of this bend makes it possible to shorten the length of the second rectilinear portion of the orifice, and in particular makes it possible to reach the outside of the core.
[0016] Dans certains modes de réalisation, l’angle entre la première et la deuxième portion rectiligne est supérieur ou égal à 100°, de préférence compris entre 110° et 120°. [0016] In some embodiments, the angle between the first and the second rectilinear portion is greater than or equal to 100 °, preferably between 110 ° and 120 °.
[0017] Ces valeurs permettent de limiter le risque, lors de l’étape de nettoyage, que des résidus de pâte céramique restent bloquées dans la partie coudée de l’orifice, si l’angle entre la première et la deuxième portion rectiligne était trop petit. Ces valeurs permettent également de limiter le volume de l’orifice traversant. Ainsi, ces valeurs d’angles entre la première et la deuxième portion rectiligne permettent de faciliter l’opération de nettoyage de l’orifice. These values make it possible to limit the risk, during the cleaning step, that ceramic paste residues remain blocked in the bent part of the orifice, if the angle between the first and the second rectilinear portion was too small. These values also make it possible to limit the volume of the through-hole. Thus, these angle values between the first and the second rectilinear portion make it possible to facilitate the operation of cleaning the orifice.
[0018] Dans certains modes de réalisation, le diamètre de la première portion rectiligne de l’orifice traversant est compris entre 0,15 et 0,3 mm. In some embodiments, the diameter of the first rectilinear portion of the through hole is between 0.15 and 0.3 mm.
[0019] Le diamètre de la première portion rectiligne peut être déterminé en fonction du diamètre de la tige de positionnement devant être insérée. De préférence, un jeu doit exister entre la tige de positionnement et l’orifice. The diameter of the first rectilinear portion can be determined as a function of the diameter of the positioning rod to be inserted. Preferably, there should be clearance between the positioning rod and the orifice.
[0020] Dans certains modes de réalisation, le diamètre de la deuxième portion rectiligne de l’orifice traversant est compris entre 0,4 et 0,6 mm. [0020] In some embodiments, the diameter of the second rectilinear portion of the through-hole is between 0.4 and 0.6 mm.
[0021] L’orifice traversant peut avoir une section circulaire. Ces valeurs permettent de faciliter l’insertion des tiges de positionnement et le nettoyage des orifices. En effet, des diamètres trop importants ne seraient pas adaptés aux techniques de nettoyage telles que l’injection d’air pulsé et/ou de solvant, et rendraient cette injection inefficace. L’opération de rebouchage des orifices serait également plus longue, plus complexe, et demanderait une quantité importante de pâte céramique pour reboucher ces orifices. De plus, des diamètres trop importants nuiraient aux propriétés mécaniques du noyau et ne permettraient pas un positionnement précis des tiges de positionnement. A l’inverse, des diamètres trop faibles empêcheraient l’insertion des tiges de positionnement. The through orifice may have a circular section. These values make it easier to insert the positioning rods and clean the holes. In fact, diameters that are too large would not be suitable for cleaning techniques such as the injection of pulsed air and / or solvent, and would make this injection ineffective. The operation of filling the orifices would also be longer, more complex, and would require a large quantity of ceramic paste to fill these orifices. In addition, too large diameters would adversely affect the mechanical properties of the core and would not allow precise positioning of the positioning rods. Conversely, diameters that are too small would prevent the insertion of the positioning rods.
[0022] Le présent exposé concerne également un procédé de fabrication d’un noyau céramique destiné à la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, le procédé comprenant une étape de fabrication d’une ébauche par le procédé selon l’un quelconque des modes de réalisation précédents, et comprenant également, après la fabrication de l’ébauche : This disclosure also relates to a method of manufacturing a ceramic core intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique, the method comprising a step of manufacturing a blank by the method according to any one of the preceding embodiments, and also comprising, after the manufacture of the blank:
- le nettoyage de l’orifice traversant, - cleaning of the through hole,
- l’insertion d’au moins une tige de positionnement dans l’orifice traversant,- the insertion of at least one positioning rod in the through hole,
- le rebouchage de l’orifice traversant, - filling the through hole,
- l’élimination de la portion de jonction. - the elimination of the junction portion.
[0023] A la fin de la fabrication de l’ébauche par fabrication additive, des résidus non solidifiés de pâte céramique restent dans l’orifice. Le nettoyage permet d’enlever ces résidus, afin de permettre l’insertion de la tige de positionnement. Par ailleurs, l’élimination de la portion de jonction peut être effectuée par frittage de la céramique à l’aide d’un outil adapté, par exemple une meule de précision élevée permettant de libérer l’espace entre la première partie et la deuxième partie. [0023] At the end of the manufacture of the blank by additive manufacturing, non-solidified residues of ceramic paste remain in the orifice. Cleaning removes these residues to allow insertion of the positioning rod. Furthermore, the elimination of the junction portion can be carried out by sintering the ceramic using a suitable tool, for example a high precision grinding wheel making it possible to free the space between the first part and the second part. .
[0024] Dans certains modes de réalisation, le nettoyage de l’orifice traversant est réalisé par une injection d’air pulsé et/ou d’un solvant dans au moins une extrémité de l’orifice. [0024] In some embodiments, the cleaning of the through orifice is achieved by injecting pulsed air and / or a solvent into at least one end of the orifice.
[0025] De l’air pulsé seul, un solvant seul, ou un mélange des deux peuvent être utilisés pour le nettoyage de l’orifice. L’air pulsé et/ou le solvant injecté à l’une des extrémités de l’orifice est évacué, en emportant les résidus de pâte céramique, par l’autre extrémité de l’orifice et/ou par le passage dans la portion de jonction. L’air pulsé et/ou le solvant injecté aux deux extrémités de l’orifice, simultanément ou non, est évacué, en emportant les résidus de pâte céramique, par le passage dans la portion de jonction. Ces techniques de nettoyage présentent l’avantage d’être facile à mettre en oeuvre, peu coûteuse, et limite considérablement le risque de casser les noyaux céramiques lors du nettoyage des orifices. Cette technique présente en outre l’avantage d’être rapide, et n’ajoute pas d’étape supplémentaire, contrairement à l’utilisation d’un foret pour nettoyer les orifices selon l’art antérieur. En effet, le nettoyage des orifices par air pulsé et/ou solvant pouvant être réalisé en même temps que le nettoyage du noyau. Pulsed air alone, a solvent alone, or a mixture of the two can be used for cleaning the orifice. The forced air and / or the solvent injected at one end of the orifice is evacuated, carrying the ceramic paste residues, through the other end of the orifice and / or through the passage in the portion of junction. The pulsed air and / or the solvent injected at both ends of the orifice, simultaneously or not, is evacuated, carrying the ceramic paste residues, through the passage in the junction portion. These cleaning techniques have the advantage of being easy to implement, inexpensive, and considerably limits the risk of breaking the ceramic cores during the cleaning of the orifices. This technique also has the advantage of being fast, and does not add an additional step, unlike the use of a drill to clean the orifices according to the prior art. In fact, the cleaning of the orifices by forced air and / or solvent can be carried out at the same time as the cleaning of the core.
[0026] Dans certains modes de réalisation, le nettoyage de l’orifice traversant est réalisé en insérant mécaniquement un moyen de nettoyage dans au moins une extrémité de l’orifice. [0026] In some embodiments, the cleaning of the through hole is achieved by mechanically inserting a cleaning means into at least one end of the hole.
[0027] Cette technique d’insertion mécanique d’un moyen de nettoyage peut être réalisée seule, ou en plus de l’air pulsé et/ou du solvant. This technique of mechanical insertion of a cleaning means can be carried out alone, or in addition to the forced air and / or the solvent.
[0028] Dans certains modes de réalisation, l’étape de nettoyage et l’étape d’insertion sont réalisées simultanément. [0028] In some embodiments, the cleaning step and the insertion step are performed simultaneously.
[0029] Selon ce mode de réalisation, le fait d’insérer la tige à une extrémité de l’orifice traversant permet de pousser les résidus de céramique, ces résidus pouvant s’échapper par l’autre extrémité de l’orifice. La tige agit ainsi elle-même comme moyen de nettoyage mécanique. [0029] According to this embodiment, the fact of inserting the rod at one end of the through hole pushes the ceramic residue, which residue can escape through the other end of the hole. The rod itself thus acts as a means of mechanical cleaning.
[0030] Dans certains modes de réalisation, les tiges de positionnement sont des tiges d’alumine. [0030] In some embodiments, the positioning rods are alumina rods.
[0031] Les tiges d’alumine sont un matériau céramique présentant l’avantage d’être résistant aux mêmes contraintes thermiques que le reste de la pièce et ayant les mêmes propriétés chimiques au décochage. Elles permettent également une grande résistance en traction/compression pour assurer la stabilité dimensionnelle de l’épaisseur de fond de baignoire, ainsi qu’une accroche solide entre la première et la deuxième partie. De manière alternative, des tiges comprenant du molybdène peuvent être utilisées. [0031] Alumina rods are a ceramic material having the advantage of being resistant to the same thermal stresses as the rest of the part and having the same chemical properties on release. They also allow great tensile / compressive strength to ensure dimensional stability of the bottom thickness of the tub, as well as a solid grip between the first and second part. Alternatively, rods comprising molybdenum can be used.
[0032] Dans certains modes de réalisation, le rebouchage de l’orifice traversant est réalisé en appliquant une pâte céramique aux deux extrémités dudit orifice. [0032] In some embodiments, the filling of the through orifice is carried out by applying a ceramic paste to both ends of said orifice.
[0033] Le rebouchage des deux extrémités de l’orifice permet d’éviter d’une part une infiltration non souhaitée de la cire lors de la fabrication du moule en cire, et d’autre part, d’obtenir un état de surface uniforme du noyau céramique, en particulier sur la première partie. Cela permet de s’assurer que la pièce finale ne présente pas d’irrégularités. [0034] Dans certains modes de réalisation, le procédé comprend, après le rebouchage, une étape de durcissement permettant de faire durcir la pâte céramique. The filling of the two ends of the orifice makes it possible to avoid on the one hand an unwanted infiltration of the wax during the manufacture of the wax mold, and on the other hand, to obtain a uniform surface condition of the ceramic core, in particular on the first part. This is to ensure that the final part does not show any irregularities. In certain embodiments, the method comprises, after filling, a hardening step making it possible to harden the ceramic paste.
[0035] L’étape de durcissement comprend par exemple une exposition sous une lampe UV permet de faire durcir la pâte céramique utilisée pour le rebouchage. Cela permet d’améliorer la rigidité globale du noyau céramique, lorsque sa fabrication est terminée. [0035] The curing step comprises, for example, exposure under a UV lamp makes it possible to harden the ceramic paste used for the filling. This improves the overall rigidity of the ceramic core, when fabrication is complete.
[0036] Dans certains modes de réalisation, avant leur insertion, les tiges de positionnement sont enduites de colle céramique. In some embodiments, before their insertion, the positioning rods are coated with ceramic glue.
[0037] Selon ce mode de réalisation, l’insertion [0037] According to this embodiment, the insertion
[0038] Le présent exposé concerne également une ébauche de noyau céramique destiné à la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, et comprenant : This disclosure also relates to a ceramic core blank intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique, and comprising:
- au moins une première partie destinée à former les cavités des aubes creuses,- at least a first part intended to form the cavities of the hollow blades,
- au moins une deuxième partie configurée pour permettre le positionnement du noyau dans un moule à cire, la deuxième partie et la première partie étant positionnées et maintenues l’une par rapport à l’autre par l’intermédiaire d’une portion de jonction intercalée entre la première partie et la deuxième partie,- at least a second part configured to allow the positioning of the core in a wax mold, the second part and the first part being positioned and held relative to each other by means of an interposed junction portion between the first part and the second part,
- au moins un orifice traversant s’étendant à travers la deuxième partie, la portion de jonction et la première partie, une première extrémité de l’orifice traversant débouchant sur une face externe de la deuxième partie, et une deuxième extrémité de l’orifice traversant débouchant sur une face externe de la première partie. - at least one through orifice extending through the second part, the junction portion and the first part, a first end of the through orifice opening onto an external face of the second part, and a second end of the orifice crossing opening onto an external face of the first part.
[0039] Le présent exposé concerne également une utilisation d’un noyau céramique obtenu par le procédé selon l’un quelconque des modes de réalisation du présent exposé, pour la fabrication d’aube de turbine creuse de turbomachine selon la technique de la fonderie à la cire perdue. This disclosure also relates to a use of a ceramic core obtained by the method according to any one of the embodiments of the present disclosure, for the manufacture of hollow turbine blade of a turbomachine according to the technique of the foundry in lost wax.
Brève description des dessins Brief description of the drawings
[0040] L'invention et ses avantages seront mieux compris à la lecture de la description détaillée faite ci-après de différents modes de réalisation de l'invention donnés à titre d'exemples non limitatifs. Cette description fait référence aux pages de figures annexées, sur lesquelles : The invention and its advantages will be better understood on reading the detailed description given below of various embodiments of the invention given by way of nonlimiting examples. This description refers to the pages of appended figures, on which:
[0041] [Fig. 1] La figure 1 représente schématiquement une vue en plan d’une portion d’un noyau céramique destiné à être utilisé pour la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, [0041] [Fig. 1] Figure 1 shows schematically a plan view of a portion of a ceramic core intended to be used for the manufacture of turbomachine hollow blades according to the lost wax casting technique,
[0042] [Fig. 2A-2B] La figure 2A représente schématiquement une technique de nettoyage d’un orifice selon l’art antérieur, et la figure 2B représente schématiquement une technique de nettoyage d’un orifice selon le présent exposé, [0042] [Fig. 2A-2B] Figure 2A schematically shows a technique for cleaning an orifice according to the prior art, and Figure 2B schematically shows a technique for cleaning an orifice according to the present disclosure,
[0043] [Fig. 3]La figure 3 représente une vue schématique en transparence d’une portion d’un noyau céramique du présent exposé, [0043] [Fig. 3] Figure 3 shows a schematic view in transparency of a portion of a ceramic core of the present disclosure,
[0044] [Fig. 4] La figure 4 est un diagramme représentant le procédé de fabrication d’un noyau céramique selon le présent exposé. [0044] [Fig. 4] Fig. 4 is a diagram showing the manufacturing process of a ceramic core according to the present disclosure.
Description des modes de réalisation Description of the embodiments
[0045] Les figures 2A et 2B représentent schématiquement des échantillons d’un noyau céramique, sous la forme d’éprouvettes, permettant d’illustrer le nettoyage d’un orifice de ce noyau. La figure 2A représente schématiquement une technique de nettoyage d’un orifice 50 selon l’art antérieur. L’orifice 50 est non débouchant. La partie hachurée représente le noyau céramique, plus précisément, la pâte polymérisée formant le noyau céramique. Ce dernier comprend une première partie 20, une deuxième partie 30, et une portion de jonction 60. La partie en grisée représente la pâte céramique non polymérisée restant dans l’orifice 50 après l’impression de l’ébauche du noyau. [0045] Figures 2A and 2B schematically show samples of a ceramic core, in the form of test pieces, illustrating the cleaning of an orifice of this core. Figure 2A schematically shows a technique for cleaning an orifice 50 according to the prior art. The orifice 50 is blind. The hatched part represents the ceramic core, more precisely, the polymerized paste forming the ceramic core. The latter comprises a first part 20, a second part 30, and a junction portion 60. The shaded part represents the unpolymerized ceramic paste remaining in the orifice 50 after the printing of the core blank.
[0046] Lors de la fabrication additive, l’ébauche de noyau est réalisée couche par couche, en commençant par la première partie 20 par exemple, puis la portion de jonction 60, puis la deuxième partie 30, en prévoyant la présence du ou des orifices 50. La portion de jonction 60 présente une forme dentelée, limitant la surface de contact entre la portion de jonction 60 et la première partie 20 et/ou la deuxième partie 30. La portion de jonction 60 peut ainsi comprendre une pluralité de dents 61 , sous la forme de picots ou de plots, intercalés entre ces deux parties. [0047] Selon le cas de figure illustré sur la figure 2A, l’orifice 50 est non débouchant et comprend un fond 51. L’opération de nettoyage de l’orifice s’effectue, par exemple, par l’intermédiaire d’un foret 70, dont le passage dans l’orifice 50 permet d’évacuer la pâte. Une telle technique entraîne la détérioration ou la casse de nombreux noyaux céramiques. During additive manufacturing, the core blank is produced layer by layer, starting with the first part 20 for example, then the junction portion 60, then the second part 30, by providing for the presence of the one or more orifices 50. The junction portion 60 has a serrated shape, limiting the contact surface between the junction portion 60 and the first part 20 and / or the second part 30. The junction portion 60 can thus comprise a plurality of teeth 61 , in the form of pins or studs, interposed between these two parts. According to the scenario illustrated in Figure 2A, the orifice 50 is non-opening and comprises a bottom 51. The operation of cleaning the orifice is carried out, for example, by means of a drill 70, the passage of which through the orifice 50 allows the dough to be evacuated. Such a technique causes deterioration or breakage of many ceramic cores.
[0048] La figure 2B représente schématiquement une technique de nettoyage d’un orifice 50 selon le présent exposé. Contrairement au cas de figure selon l’art antérieur, l’orifice 50 est débouchant. Plus précisément, l’orifice 50 comprend une première portion rectiligne 50a s’étendant à travers la deuxième partie 30, la portion de jonction 60 et la première partie 20, et une deuxième portion rectiligne 50b s’étendant à travers la première partie 20 depuis l’extrémité de la première portion rectiligne 50a, et débouchant sur une face externe de la première partie 20. La première portion rectiligne 50a est de préférence plus longue que la deuxième portion rectiligne 50b, et est destinée à recevoir une tige de positionnement. L’angle b entre la première et la deuxième portion rectiligne 50a, 50b est inférieur à 180 ° , et supérieur ou égal à 100 ° , de préférence compris entre 110° et 120°. [0048] Figure 2B schematically shows a technique for cleaning an orifice 50 according to the present disclosure. Unlike the case according to the prior art, the orifice 50 is through. More specifically, the orifice 50 comprises a first rectilinear portion 50a extending through the second part 30, the junction portion 60 and the first part 20, and a second rectilinear portion 50b extending through the first part 20 from the end of the first rectilinear portion 50a, and opening onto an external face of the first part 20. The first rectilinear portion 50a is preferably longer than the second rectilinear portion 50b, and is intended to receive a positioning rod. The angle b between the first and the second rectilinear portion 50a, 50b is less than 180 °, and greater than or equal to 100 °, preferably between 110 ° and 120 °.
[0049] Lors de la fabrication additive, un passage 62 est prévu dans la portion de jonction 60. Ce passage 62 peut être un orifice, ou une absence locale de dents 61 , permettant de mettre l’orifice 50 en communication fluidique avec une région externe au noyau céramique, et entourant celui-ci. Ce passage 62 permet de faciliter l’opération de nettoyage de l’orifice 50. En effet, à la fin de la fabrication additive, le nettoyage de l’orifice 50 peut s’effectuer en injectant de l’air pulsé à l’une ou aux deux extrémités de l’orifice 50. La pression exercée aux extrémités de l’orifice 50 permet l’évacuation de la pâte non polymérisée présente dans l’orifice, par le passage 62 de la portion de jonction 60 (cf. flèches sur la figure 2A). A la place de l’air pulsé, un solvant peut être injecté, ou un mélange d’air et de solvant. De manière alternative, un outil cylindrique de diamètre adapté peut être utilisé pour pousser la pâte, en plus ou la place de l’air et/ou du solvant. During additive manufacturing, a passage 62 is provided in the junction portion 60. This passage 62 can be an orifice, or a local absence of teeth 61, making it possible to put the orifice 50 in fluid communication with a region external to the ceramic core, and surrounding it. This passage 62 makes it possible to facilitate the operation of cleaning the orifice 50. In fact, at the end of the additive manufacturing process, the cleaning of the orifice 50 can be carried out by injecting pulsed air into one. or at both ends of the orifice 50. The pressure exerted at the ends of the orifice 50 allows the discharge of the unpolymerized paste present in the orifice, through the passage 62 of the junction portion 60 (see arrows on Figure 2A). Instead of forced air, a solvent can be injected, or a mixture of air and solvent. Alternatively, a cylindrical tool of suitable diameter can be used to push the paste, in addition to or in place of air and / or solvent.
[0050] La figure 3 représente une vue schématique d’une partie d’un noyau céramique 10 selon le présent exposé, réalisé par fabrication additive, comprenant une première partie 20, une deuxième partie 30, et une portion de jonction 60. La première partie 20 présente la forme des cavités que l’on souhaite obtenir à la fin de la fabrication de l’aube de turbine. Sur la figure 3, seule l’extrémité supérieure de la première partie 20, correspondant à l’extrémité supérieure, ou sommet, de l’aube, est visible. La deuxième partie 30, ou dôme, permet le maintien du noyau céramique 10 lors de la réalisation du modèle en cire, et lors de la coulée du métal dans un moule carapace céramique. La première partie 20 et la deuxième partie 30 sont espacées l’une de l’autre d’une distance S comprise entre 0,4 et 1 ,4 mm. Cet espacement, et ce positionnement de la première partie 20 par rapport à la deuxième partie 30 sont assurés, à la fin de la fabrication de l’ébauche de noyau, par la portion de jonction 60. Après l’élimination de la portion de jonction 60, l’espace S demeurant entre ces deux parties permet la formation de la baignoire au sommet de l’aube, lors de la coulée du métal s’infiltrant dans cet espace. Figure 3 shows a schematic view of part of a ceramic core 10 according to the present disclosure, produced by additive manufacturing, comprising a first part 20, a second part 30, and a junction portion 60. The first part 20 shows the shape of the cavities you want get at the end of manufacturing the turbine blade. In FIG. 3, only the upper end of the first part 20, corresponding to the upper end, or top, of the blade, is visible. The second part 30, or dome, allows the maintenance of the ceramic core 10 during the production of the wax model, and during the casting of the metal in a ceramic shell mold. The first part 20 and the second part 30 are spaced from each other by a distance S of between 0.4 and 1.4 mm. This spacing, and this positioning of the first part 20 relative to the second part 30 are ensured, at the end of the manufacturing of the core blank, by the junction portion 60. After the elimination of the junction portion 60, the space S remaining between these two parts allows the formation of the tub at the top of the blade, during the casting of the metal infiltrating this space.
[0051 ] Dans cet exemple, trois orifices traversants 50 s’étendent à travers la deuxième partie 30, la portion de jonction 60 et la première partie 20. Chacun de ces orifices 50 comprend une première portion rectiligne 50a débouchant sur une face externe de la deuxième partie 30, et une deuxième portion rectiligne 50b (dont une seule est visible sur la figure 3) débouchant une face externe de la première partie 20. Une tige de positionnement 40 est insérée dans chacun de ces orifices 50. Ces tiges de positionnement 40 peuvent être des tiges d’alumine, et peuvent présenter une longueur de 13 mm et un diamètre de 0,6 mm. Néanmoins, ces dimensions ne sont pas limitatives, et peuvent être modifiées en fonction de la géométrie considérée du noyau. In this example, three through orifices 50 extend through the second part 30, the junction portion 60 and the first part 20. Each of these orifices 50 comprises a first rectilinear portion 50a opening onto an outer face of the second part 30, and a second rectilinear portion 50b (only one of which is visible in FIG. 3) opening out an external face of the first part 20. A positioning rod 40 is inserted into each of these orifices 50. These positioning rods 40 may be alumina rods, and may have a length of 13 mm and a diameter of 0.6 mm. However, these dimensions are not limiting, and can be modified according to the geometry considered of the core.
[0052] La suite de la description décrit un procédé de fabrication d’un noyau céramique 10 selon le présent exposé, en référence à la figure 4. The remainder of the description describes a method of manufacturing a ceramic core 10 according to the present disclosure, with reference to Figure 4.
[0053] Une première étape de la fabrication d’un noyau céramique 10 comprend la fabrication d’une ébauche du noyau par fabrication additive (étape S1). L’ébauche comprend la première partie 20, la portion de jonction 60 et la deuxième partie 30. La fabrication additive prévoit la présence des orifices traversants 50, et du ou des passage(s) 62 dans la portion de jonction 60. A first step in the manufacture of a ceramic core 10 comprises the manufacture of a blank of the core by additive manufacturing (step S1). The blank comprises the first part 20, the junction portion 60 and the second part 30. Additive manufacturing provides for the presence of the through holes 50, and of the passage (s) 62 in the junction portion 60.
[0054] A la fin de la fabrication de l’ébauche, les orifices 50 sont nettoyés, c’est- à-dire vidées des résidus de pâte céramique non polymérisée demeurant dans les orifices 50 (étape S2). Pour ce faire, de l’air pulsé et/ou du solvant, par exemple, est injecté aux extrémités des orifices 50. La pâte résiduelle est ainsi évacuée par le passage 62 de la portion de jonction 60. At the end of the manufacture of the blank, the orifices 50 are cleaned, that is to say emptied of the residues of unpolymerized ceramic paste remaining in the orifices 50 (step S2). To do this, forced air and / or solvent, for example For example, is injected at the ends of the orifices 50. The residual paste is thus discharged through the passage 62 of the junction portion 60.
[0055] Une tige de positionnement 40 est ensuite insérée dans chaque orifice traversant 50 (étape S3). Plus précisément, une tige de positionnement 40 est insérée dans la première portion rectiligne 50a de chaque orifice traversant. Les tiges 40 sont insérées par le haut, c’est-à-dire par l’extrémité de l’orifice 50 débouchant sur une face externe de la deuxième partie 30, et enfoncées dans l’orifice 50 de manière à s’étendre à la fois dans la deuxième partie 30 et dans la première partie 20. Les tiges 40 peuvent être préalablement enduites de colle céramique. Cette colle se solidifie lors du traitement thermique décrit ci-dessous, et permet un enrobage optimal de la tige. A positioning rod 40 is then inserted into each through hole 50 (step S3). More precisely, a positioning rod 40 is inserted into the first rectilinear portion 50a of each through hole. The rods 40 are inserted from the top, that is to say through the end of the orifice 50 opening onto an external face of the second part 30, and pressed into the orifice 50 so as to extend to both in the second part 30 and in the first part 20. The rods 40 can be coated beforehand with ceramic glue. This adhesive solidifies during the heat treatment described below, and allows optimal coating of the rod.
[0056] Après la mise en place des tiges de positionnement 40 dans les orifices 50, ces derniers sont rebouchés (étape S4). Ce rebouchage est effectué à l’aide d’une pâte céramique, de manière à obtenir un état de surface lisse, sur les faces externes des première et deuxième parties 20 et 30. Cela permet d’éviter des irrégularités de surface ultérieurement sur le modèle en cire, et sur la pièce finale. Le rebouchage est suivi d’une étape de durcissement de la pâte céramique, permettant de solidifier la pâte ajoutée à l’étape S4 (étape S5). Cette étape peut être réalisée en fonction des propriétés de la pâte, selon qu’elle soit, par exemple, photosensible ou thermosensible, par l’intermédiaire notamment d’une source de lumière UV ou une source de chaleur. Selon ce mode de réalisation, l’étape de durcissement est réalisée par une exposition à la lumière UV. On notera qu’après solidification de la pâte céramique, le noyau 10 peut également suivre une étape de traitement thermique, comprenant le déliantage et le frittage. After the positioning of the positioning rods 40 in the orifices 50, the latter are plugged (step S4). This filling is carried out using a ceramic paste, so as to obtain a smooth surface condition, on the external faces of the first and second parts 20 and 30. This makes it possible to avoid surface irregularities subsequently on the model. in wax, and on the final piece. The filling is followed by a step of hardening the ceramic paste, making it possible to solidify the paste added in step S4 (step S5). This step can be carried out depending on the properties of the paste, depending on whether it is, for example, photosensitive or heat-sensitive, in particular by means of a UV light source or a heat source. According to this embodiment, the curing step is performed by exposure to UV light. It will be noted that after solidification of the ceramic paste, the core 10 can also follow a heat treatment step, comprising debinding and sintering.
[0057] Le procédé comprend enfin l’élimination de la portion de jonction 60 (étape S6). Cette élimination est facilitée par la forme dentelée de la partie de jonction 60, et peut être réalisée par n’importe quel outil adapté, pouvant s’insérer entre la première partie et la deuxième partie. A la fin de cette étape, la première partie 20 et la deuxième partie 30 sont maintenues l’une à l’autre, et positionnées l’une par rapport à l’autre, par les tiges de positionnement 40 uniquement. [0058] Le noyau céramique 10 ainsi obtenu peut être ensuite utilisé dans la fabrication d’aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue. En particulier, le noyau céramique 10 peut être disposé dans un moule à cire, en étant maintenu par la deuxième partie 30, pour former la modèle en cire présentant la forme de la pièce finale, avec les cavités formées par la première partie 20 du noyau céramique 10. Le modèle en cire est ensuite plongé à plusieurs reprises dans une barbotine afin de former le moule céramique.The method finally comprises the elimination of the junction portion 60 (step S6). This elimination is facilitated by the serrated shape of the junction part 60, and can be achieved by any suitable tool, which can be inserted between the first part and the second part. At the end of this step, the first part 20 and the second part 30 are held together, and positioned with respect to each other, by the positioning rods 40 only. The ceramic core 10 thus obtained can then be used in the manufacture of hollow turbomachine blades according to the lost wax casting technique. In particular, the ceramic core 10 can be placed in a wax mold, being held by the second part 30, to form the wax model having the shape of the final part, with the cavities formed by the first part 20 of the core. ceramic 10. The wax model is then dipped several times in a slip to form the ceramic mold.
Après élimination de la cire, le métal fondu est coulé dans le moule céramique et autour du noyau céramique, ce dernier étant à nouveau maintenu en position fixe par l’intermédiaire de la deuxième partie 30. Enfin, le moule céramique et le noyau céramique 10 sont ensuite éliminés, par exemple par décochage, afin d’obtenir la pièce finale. On notera que l’élimination de la céramique comprend également l’élimination des tiges 40 d’alumine de positionnement, retirées pendant le décochage, laissant alors de petits orifices à travers la baignoire au sommet de l’aube, à l’endroit où se trouvaient ces tiges. Ces orifices servent notamment de trous de dépoussiérage ou d’évacuation de l’air présent dans les cavités de l’aube. After removal of the wax, the molten metal is poured into the ceramic mold and around the ceramic core, the latter being again held in a fixed position by means of the second part 30. Finally, the ceramic mold and the ceramic core 10 are then eliminated, for example by unhooking, in order to obtain the final part. Note that the removal of the ceramic also includes the removal of the positioning alumina rods 40, removed during the unhooking, then leaving small holes through the tub at the top of the vane, where it sits. were finding these rods. These orifices serve in particular as dust removal or evacuation holes for the air present in the cavities of the vane.
[0059] Bien que la présente invention ait été décrite en se référant à des exemples de réalisation spécifiques, il est évident que des modifications et des changements peuvent être effectués sur ces exemples sans sortir de la portée générale de l'invention telle que définie par les revendications. En particulier, des caractéristiques individuelles des différents modes de réalisation illustrés/mentionnés peuvent être combinées dans des modes de réalisation additionnels. Par conséquent, la description et les dessins doivent être considérés dans un sens illustratif plutôt que restrictif. Although the present invention has been described with reference to specific embodiments, it is obvious that modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the revendications. In particular, individual characteristics of the different illustrated / mentioned embodiments can be combined in additional embodiments. Therefore, the description and the drawings should be taken in an illustrative rather than a restrictive sense.
[0060] Il est également évident que toutes les caractéristiques décrites en référence à un procédé sont transposables, seules ou en combinaison, à un dispositif, et inversement, toutes les caractéristiques décrites en référence à un dispositif sont transposables, seules ou en combinaison, à un procédé. It is also obvious that all the characteristics described with reference to a method can be transposed, alone or in combination, to a device, and conversely, all the characteristics described with reference to a device can be transposed, alone or in combination, to a method.

Claims

Revendications Claims
[Revendication 1] Procédé de fabrication d'une ébauche d'un noyau céramique (10) destiné à la fabrication d'aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, l'ébauche étant fabriquée par fabrication additive et comprenant : [Claim 1] A method of manufacturing a blank of a ceramic core (10) intended for manufacturing hollow turbomachine blades according to the lost wax casting technique, the blank being manufactured by additive manufacturing and comprising :
- au moins une première partie (20) destinée à former les cavités des aubes creuses, - at least a first part (20) intended to form the cavities of the hollow blades,
- au moins une deuxième partie (30) configurée pour permettre le positionnement du noyau (10) dans un moule à cire, la deuxième partie (30) et la première partie (20) étant positionnées et maintenues l'une par rapport à l'autre par l'intermédiaire d'une portion de jonction temporaire (60) intercalée entre la première partie (20) et la deuxième partie (30), - at least a second part (30) configured to allow the positioning of the core (10) in a wax mold, the second part (30) and the first part (20) being positioned and held one relative to the another by means of a temporary junction portion (60) interposed between the first part (20) and the second part (30),
- au moins un orifice traversant (50) s'étendant à travers la deuxième partie (30), la portion de jonction temporaire (60) et la première partie (20), une première extrémité de l'orifice traversant (50) débouchant sur une face externe de la deuxième partie (30), et une deuxième extrémité de l'orifice traversant (50) débouchant sur une face externe de la première partie (20). - at least one through orifice (50) extending through the second part (30), the temporary junction portion (60) and the first part (20), a first end of the through orifice (50) opening onto an outer face of the second part (30), and a second end of the through orifice (50) opening onto an outer face of the first part (20).
[Revendication 2] Procédé selon la revendication 1, dans lequel la portion de jonction temporaire (60) comprend un passage (62) mettant en communication fluidique l'orifice traversant (50) et un espace extérieur à l'ébauche de noyau. [Claim 2] The method of claim 1, wherein the temporary junction portion (60) comprises a passage (62) fluidly communicating the through-port (50) and a space exterior to the core blank.
[Revendication 3] Procédé selon la revendication 1 ou 2, dans lequel l'orifice traversant (50) comprend une première portion rectiligne (50a) s'étendant depuis la première extrémité, et une deuxième portion rectiligne (50b) présentant un angle (b) inférieur à 180° par rapport à la première portion rectiligne (50a), et s'étendant depuis la deuxième extrémité. [Claim 3] A method according to claim 1 or 2, wherein the through-hole (50) comprises a first rectilinear portion (50a) extending from the first end, and a second rectilinear portion (50b) having an angle (b ) less than 180 ° with respect to the first rectilinear portion (50a), and extending from the second end.
[Revendication 4] Procédé selon la revendication 3, dans lequel l'angle (b) entre la première et la deuxième portion rectiligne (50a, 50b) est supérieur ou égal à 100°, de préférence compris entre 110° et 120°. [Claim 4] A method according to claim 3, wherein the angle (b) between the first and the second rectilinear portion (50a, 50b) is greater than or equal to 100 °, preferably between 110 ° and 120 °.
[Revendication 5] Procédé selon l'une quelconque des revendications 1 à 4, dans lequel le diamètre de la première portion rectiligne (50a) de l'orifice traversant (50) est compris entre 0,15 et 0,3 mm. [Claim 5] A method according to any one of claims 1 to 4, wherein the diameter of the first rectilinear portion (50a) of the through hole (50) is between 0.15 and 0.3 mm.
[Revendication 6] Procédé de fabrication d'un noyau céramique (10) destiné à la fabrication d'aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, le procédé comprenant une étape de fabrication d'une ébauche par le procédé selon l'une quelconque des revendications 1 à 5, et comprenant également, après la fabrication de l'ébauche : [Claim 6] A method of manufacturing a ceramic core (10) intended for manufacturing hollow turbomachine blades according to the lost wax casting technique, the method comprising a step of manufacturing a blank by the method according to any one of claims 1 to 5, and also comprising, after manufacture of the blank:
- le nettoyage de l'orifice traversant (50), - cleaning the through hole (50),
- l'insertion d'au moins une tige de positionnement (40) dans l'orifice traversant (50), - the insertion of at least one positioning rod (40) in the through hole (50),
- le rebouchage de l'orifice traversant (50), - filling the through hole (50),
- l'élimination de la portion de jonction temporaire (60). - elimination of the temporary junction portion (60).
[Revendication 7] Procédé selon la revendication 6, dans lequel le nettoyage de l'orifice traversant (50) est réalisé par une injection d'air pulsé et/ou d'un solvant dans au moins une extrémité de l'orifice (50). [Claim 7] A method according to claim 6, wherein the cleaning of the through orifice (50) is carried out by injecting pulsed air and / or a solvent into at least one end of the orifice (50). .
[Revendication 8] Procédé selon la revendication 6 ou 7, dans lequel les tiges de positionnement (40) sont des tiges d'alumine. [Claim 8] A method according to claim 6 or 7, wherein the positioning rods (40) are alumina rods.
[Revendication 9] Procédé selon l'une quelconque des revendications 6 à 8, dans lequel le rebouchage de l'orifice traversant (50) est réalisé en appliquant une pâte céramique aux deux extrémités dudit orifice (50). [Claim 9] A method according to any one of claims 6 to 8, wherein the filling of the through hole (50) is carried out by applying a ceramic paste to both ends of said hole (50).
[Revendication 10] Procédé selon l'une quelconque des revendications 6 à 9, comprenant, après le rebouchage, une étape de durcissement permettant de faire durcir la pâte céramique utilisée pour le rebouchage de l'orifice (50). [Claim 10] A method according to any one of claims 6 to 9, comprising, after the filling, a hardening step making it possible to harden the ceramic paste used for filling the orifice (50).
[Revendication 11] Procédé selon l'une quelconque des revendications 6 à 10, dans lequel, avant leur insertion, les tiges de positionnement (40) sont enduites de colle céramique. [Claim 11] A method according to any one of claims 6 to 10, wherein, before their insertion, the positioning rods (40) are coated with ceramic glue.
[Revendication 12] Ebauche de noyau céramique destiné à la fabrication d'aubes creuses de turbomachine selon la technique de la fonderie à la cire perdue, comprenant : [Claim 12] A blank for a ceramic core intended for the manufacture of hollow turbomachine blades according to the lost wax casting technique, comprising:
- au moins une première partie (20) destinée à former les cavités des aubes creuses, - at least a first part (20) intended to form the cavities of the hollow blades,
- au moins une deuxième partie (30) configurée pour permettre le positionnement du noyau dans un moule à cire, la deuxième partie (30) et la première partie (20) étant positionnées et maintenues l'une par rapport à l'autre par l'intermédiaire d'une portion de jonction temporaire (60) intercalée entre la première partie (20) et la deuxième partie (30), - at least a second part (30) configured to allow the positioning of the core in a wax mold, the second part (30) and the first part (20) being positioned and held relative to each other by the 'intermediate a temporary junction portion (60) interposed between the first part (20) and the second part (30),
- au moins un orifice traversant (50) s'étendant à travers la deuxième partie (30), la portion de jonction temporaire (60) et la première partie (20), une première extrémité de l'orifice traversant (50) débouchant sur une face externe de la deuxième partie (30), et une deuxième extrémité de l'orifice traversant (50) débouchant sur une face externe de la première partie (20). - at least one through orifice (50) extending through the second part (30), the temporary junction portion (60) and the first part (20), a first end of the through orifice (50) opening onto an outer face of the second part (30), and a second end of the through orifice (50) opening onto an outer face of the first part (20).
[Revendication 13] Procédé de fabrication d'aube de turbine creuse de turbomachine selon la technique de la fonderie à la cire perdue, comprenant :[Claim 13] A method of manufacturing a turbomachine hollow turbine blade according to the lost wax casting technique, comprising:
- la fabrication d'un noyau céramique (10) par un procédé selon l'une quelconque des revendications 6 à 11, - the manufacture of a ceramic core (10) by a method according to any one of claims 6 to 11,
- la fabrication d'un modèle en cire présentant la forme de la pièce finale, en disposant le noyau céramique (10) obtenu à l'étape précédente dans un moule à cire, - the manufacture of a wax model having the shape of the final part, by placing the ceramic core (10) obtained in the previous step in a wax mold,
- la fabrication d'un moule céramique, en plongeant à plusieurs reprises dans une barbotine le modèle en cire obtenu à l'étape précédente, - the manufacture of a ceramic mold, by dipping several times in a slip the wax model obtained in the previous step,
- la coulée, après élimination de la cire, de métal fondu dans le moule céramique et autour du noyau céramique, - the casting, after removal of the wax, of molten metal in the ceramic mold and around the ceramic core,
- l'élimination du moule céramique et du noyau céramique (10). - elimination of the ceramic mold and the ceramic core (10).
EP20775042.3A 2019-08-30 2020-08-27 Improved method for manufacturing a ceramic core for manufacturing turbomachine vanes and ceramic core Active EP4021663B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1909534A FR3100143B1 (en) 2019-08-30 2019-08-30 Improved method of manufacturing a ceramic core for the manufacture of turbine engine blades
PCT/FR2020/051507 WO2021038174A1 (en) 2019-08-30 2020-08-27 Improved method for manufacturing a ceramic core for manufacturing turbomachine vanes

Publications (2)

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EP4021663A1 true EP4021663A1 (en) 2022-07-06
EP4021663B1 EP4021663B1 (en) 2023-07-05

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EP (1) EP4021663B1 (en)
CN (1) CN114340815B (en)
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WO (1) WO2021038174A1 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR3120807B1 (en) * 2021-03-16 2023-12-01 Safran Aircraft Engines Lost wax casting manufacturing process
FR3121372B1 (en) * 2021-03-30 2023-03-31 Safran System for inserting rods into a ceramic core blank for the manufacture of turbomachine blades

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FR2889088B1 (en) * 2005-07-29 2008-08-22 Snecma CORE FOR BLADE OF TURBOMACHINE
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CN101468384A (en) 2007-12-25 2009-07-01 南通华东液压铸业有限公司 Multi-layer multiplex hydraulic valve mold and casting technique thereof
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CN114340815B (en) 2023-12-05
CN114340815A (en) 2022-04-12
US11745255B2 (en) 2023-09-05
WO2021038174A1 (en) 2021-03-04
EP4021663B1 (en) 2023-07-05
FR3100143B1 (en) 2021-11-12
FR3100143A1 (en) 2021-03-05
US20220288671A1 (en) 2022-09-15

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