EP3288699B1 - Method for producing a pattern for investment casting - Google Patents
Method for producing a pattern for investment casting Download PDFInfo
- Publication number
- EP3288699B1 EP3288699B1 EP16722312.2A EP16722312A EP3288699B1 EP 3288699 B1 EP3288699 B1 EP 3288699B1 EP 16722312 A EP16722312 A EP 16722312A EP 3288699 B1 EP3288699 B1 EP 3288699B1
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- EP
- European Patent Office
- Prior art keywords
- model
- portions
- pattern
- insert
- blade
- Prior art date
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- 238000004519 manufacturing process Methods 0.000 title claims description 59
- 238000005495 investment casting Methods 0.000 title description 12
- 238000000034 method Methods 0.000 claims description 46
- 239000000463 material Substances 0.000 claims description 20
- 238000005266 casting Methods 0.000 claims description 15
- 238000007789 sealing Methods 0.000 claims description 9
- 239000000654 additive Substances 0.000 claims description 7
- 230000000996 additive effect Effects 0.000 claims description 7
- 238000001746 injection moulding Methods 0.000 claims description 4
- 238000003466 welding Methods 0.000 claims description 3
- 239000000853 adhesive Substances 0.000 claims description 2
- 230000001070 adhesive effect Effects 0.000 claims description 2
- 239000002184 metal Substances 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 238000010438 heat treatment Methods 0.000 description 5
- 238000000465 moulding Methods 0.000 description 4
- 238000004026 adhesive bonding Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 229920003229 poly(methyl methacrylate) Polymers 0.000 description 3
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- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000008030 elimination Effects 0.000 description 2
- 238000003379 elimination reaction Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 101100536354 Drosophila melanogaster tant gene Proteins 0.000 description 1
- 241001080024 Telles Species 0.000 description 1
- 238000004873 anchoring Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
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- 238000007599 discharging Methods 0.000 description 1
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- 229910052742 iron Inorganic materials 0.000 description 1
- 238000005304 joining Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
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- 229920000620 organic polymer Polymers 0.000 description 1
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Images
Classifications
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- 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
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- 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
- B22C7/023—Patterns made from expanded plastic materials
- B22C7/026—Patterns made from expanded plastic materials by assembling preformed parts
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C13/00—Moulding machines for making moulds or cores of particular shapes
- B22C13/08—Moulding machines for making moulds or cores of particular shapes for shell moulds or shell cores
- B22C13/085—Moulding machines for making moulds or cores of particular shapes for shell moulds or shell cores by investing a lost pattern
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
- B22C9/04—Use of lost patterns
-
- 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
Definitions
- the invention relates to the manufacture of investment casting patterns.
- 'lost pattern foundry pattern' or more simply 'foundry pattern' or even 'pattern' here is meant a part made at least in part from an eliminable material, and having substantially the same shape as the part that the we are trying to make.
- the material is removable means in the present context (from a foundry pattern) that this material is capable of being removed without destroying or damaging the mold formed around the foundry pattern. This elimination can be done chemically (baths, etc.), and/or thermal, or other.
- the removable material may simply be a low temperature fusible material.
- the expression 'low temperature fuse' here means fuse at a temperature below 500°C, and preferably below 100°C.
- a model can include one or more inserts, which are parts integrated into the model either to allow the manufacture of the latter, or to form part of the part that one seeks to manufacture.
- Investment casting is a known process usually comprising the following steps: casting patterns are produced; a shell mold is formed around these models; the models are then eliminated (with the exception of any insert(s)) by heating the mould: the models melt and/or burn (with the exception of any insert(s); the material which constitutes them is then evacuated from the mould. The shell mold is then used to make the parts by foundry.
- the invention relates more specifically to the manufacture of investment casting patterns comprising an insert.
- Such models are used either to manufacture parts which themselves include an insert, or to manufacture hollow parts: in the latter case, the insert of the foundry model is a core, which is used to arrange the hollow part of the part during the casting of the molten metal, and is then eliminated after the metal mass has cooled.
- digital definition refers to the digital file defining the shape (in three dimensions) of a part, for example the shape of a model to be manufactured. This file is usually obtained using software CAD such as CATIA (registered trademark of the company DASSAULT SYSTEMES)).
- the object of the invention is therefore to propose a process for the manufacture of foundry patterns, for the manufacture of foundry patterns comprising an insert, which is faster and less expensive than the traditional process described above.
- the insert(s) may in particular comprise a core, intended to be removed after the casting step during investment casting.
- This or these cores may in particular be one or more ceramic cores.
- One or more insert(s) can also be permanent inserts, intended to be integrated into the part, for example to reinforce it mechanically.
- the joining of said at least two portions forms the model. Therefore, the shape of the model is the meeting of the shapes (or volumes) of the different portions.
- the foundry pattern is made by assembling several portions of the pattern, the process below gives great increased flexibility, compared to the traditional process by injection molding in a mould.
- the different portions of the model are easier to manufacture, each, than the model itself; in particular, because these portions do not include an insert.
- step S1B) of manufacturing one or more of the model portions can be performed by manufacturing one or more of said model portions by an additive process. It can also be done by injection. It can also be made by any other process suitable for the manufacture of a model portion.
- step S1A) of supplying the insert(s) can be carried out by manufacturing the insert(s) by an additive process, by injection or by any another suitable method.
- step S2 The production of the model by assembling its portions around the insert or inserts, in step S2), however, requires certain precautions to be taken.
- the term "tight" means the fact that the connection zones between the model portions and the insert and/or between the model portions between them do not allow any foreign body to pass, in the same way as the useful parts of the rest of the model.
- step S2 the said at least two model portions are fixed to one another or to each other in a sealed manner around at least a part of the said at least one insert”.
- said at least two model portions are thus assembled in a sealed manner around the entire insert.
- the insert(s) do not protrude outside the model: they are strictly contained inside the latter and separated in a sealed manner from the space outside the model.
- the model portions are assembled in a sealed manner around only part of the insert.
- the insert(s) may protrude outside the model; the parts of the inserts that protrude are called appendages.
- the model portions are assembled in a sealed manner around the appendages.
- These appendages of the insert(s) protruding from the model portion(s) may prove useful in the molding process, in particular for anchoring the insert in the shell, for example for respecting the wall thicknesses on the final part. or for the maintenance and dimensional control of the hollow cavity.
- thermofusible material the melting properties of this material can be used locally to seal the foundry pattern during the manufacturing step S2) .
- any other method suitable for making this model leaktight during step S2) can be used (in particular by adding sealing resin or the like), in particular if the model portions are not made of thermofusible material.
- the method is applicable in particular to the manufacture of foundry models comprising an aerodynamic profile.
- the method is applicable in particular to the manufacture of foundry models comprising a blade.
- step S1B in a preferred embodiment of the method, exactly two portions of the model are provided, an underside portion including the part of the blade located on the underside side, and an extrados portion including the part of the blade situated on the side of the extrados.
- the invention also relates to a method of manufacturing a part in investment casting, in which a model is manufactured by the method presented previously.
- the blade manufacturing process presented on the figure 1 is an investment casting process.
- the method is presented in the context of the manufacture of a cluster of twelve blades for a turbomachine.
- the method comprises seven steps S1 to S7. Steps S1 and S2 are identical for each of the twelve blades. They will therefore be described in the context of a (single) blade; it is necessary in practice to carry out these steps for each of the twelve blades.
- This operation can be done by any means.
- One method is to create the digital definitions of the portions of the model from the digital definition of the part.
- the room is divided into several portions.
- the part can be divided into an extrados portion 12 including the part of the blade located on the side of the extrados, and a intrados portion 14 including the part of the blade located on the side of the intrados.
- the model 16 is then the union of two portions, an intrados portion 14 and an extrados portion 12, which correspond to the parts of the blade located respectively on the intrados side and on the extrados side ( Fig.3 ).
- the model portions can be defined with junction zones presenting shape complementarities (cones, stair steps, etc.). These shape complementarities are used, when assembling the model portions, to ensure the correct relative positioning of the different model portions, which is important to ensure that the resulting model has the shape as close as possible to that specified by the digital definition of the part.
- the model portions can further be defined with recesses and/or housings, provided to cooperate with corresponding parts of the core, so that the core is precisely held in position by the blade portions inside the dawn pattern.
- the core 10 can also be produced by an additive process, or even conventionally by injection/firing.
- Methods other than heating can be envisaged for the elimination of model portions.
- the removal can be chemically, by hypercritical debinding, etc.
- a cluster 20 of wax models ( Fig.2 ), also called 'non-permanent cluster'.
- This cluster 20 is used to manufacture a shell mold by forming hollow volumes in the shell mold, in a manner known per se.
- the cluster 20 is manufactured by assembling the blade models 16 made in step S2 using prefabricated auxiliary elements 22.
- auxiliary elements 22 are used to form the technical parts of the shell mould, in particular the metal supply and evacuation channels, the thermal screens, etc. They comprise in particular two parallel discs 24, each of these discs having the shape of a plate pierced with holes through which the blade models 16 pass.
- the 16 vane models are all identical to each other. They are arranged in a circle axisymmetrically around an X axis, called the casting axis.
- the X axis is arranged in the vertical direction during the foundry operation, when molten metal is poured into the shell mold (discussed in more detail below).
- the blade models 16 will be used to arrange molding cavities for the molding of blades; the auxiliary elements 22 will be used to arrange in particular a pouring cup, supply channels, stiffeners and selectors.
- step S4 the shell mold is manufactured by immersing the non-permanent cluster 20 in a slip from which the shell is formed (this step as well as the subsequent steps S5 to S7 are described in more detail by the document WO2014/049223 ).
- the blade models are eliminated by heating the shell mold in which the non-permanent cluster is located. Under the effect of heat, the blade models melt and/or burn, which makes it possible to eliminate them and free the interior volume of the shell mould.
- the cluster of castings - that is to say the cluster of blades - is then formed in the shell mold by pouring molten metal into the latter.
- a sixth step S6 after cooling and solidification of the metal in the shell mould, the blade cores are removed by soaking in a basic chemical bath, and the cluster of blades is removed from the shell mould.
- each of the blades is separated from the rest of the cluster and finished by machining processes and/or surface treatments.
- the invention relates more particularly to steps S1 and S2, that is to say the manufacture of the blade models 16.
- steps S1 and S2 that is to say the manufacture of the blade models 16.
- An example of implementation of these steps is illustrated by the figures 3 to 6 .
- the blade model 16 is a wax model of a blade comprising a blade 30 and a root 32.
- FIG. 3 represents the blade model 16 obtained by assembling three components, namely the upper surface part 12, the core 10 and the lower surface part 14 ( Fig.4 ).
- THE figure 5 And 6 represent a section of the model 16 in a plane P perpendicular to its longitudinal axis.
- the blade that the blade model 16 is used to manufacture is a hollow blade. Also, for the manufacture of the latter by investment casting, it is necessary to use a core - in this case the core 10.
- the shape of the core 10 delimits the interior volume of the blade that is sought. to be kept empty, that is to say the interior volume of the blade which must not be filled with metal during casting.
- the model portions 12 and 14 are provided with frustoconical projections 11, and the core 10 is provided with corresponding holes 11 of frustoconical shape, which allow the core 10 to be held in precise relative position with respect to the model portions 12 and 14.
- Core 10 is made separately from ceramic during step S1A, in a manner known per se (for example by molding in a core box, or by additive manufacturing, for example by powder sintering). It consists mainly of silica.
- Its material is selected so that its melting temperature is above 1300°C. Thanks to this, the core does not melt during step S5 of casting the cluster of blades. Conversely, this material is selected so that it can be eliminated by chemical solvents during step S6.
- Model portions 12 and 14 are fabricated separately (step S1B). They are made of removable material: in the present case, of low-temperature fusible material. They can for example be manufactured by rapid prototyping, by deposition of wax filament or by powder sintering. They can be made, for example, of PMMA (polymethyl methacrylate) or in other organic polymers. These materials can be eliminated by being brought to a temperature of the order of 1000° C. in a burning oven, during step S5 before casting the metal.
- PMMA polymethyl methacrylate
- the shape of the model portions 12 and 14 is such that the combination of their volumes substantially corresponds to the volume of the blade that it is desired to manufacture.
- Portions 12 and 14 are in contact at two contact surfaces: an upstream contact surface 15 and a downstream contact surface 17. These surfaces are defined in such a way that the union of core 10, portions 12 and 14 is easily and without difficulties related to undercuts or other.
- step S21 a thin layer of adhesive is deposited on the contact surfaces 15 and 17; the portions 12 and 14 are glued together, the core 10 being placed between them.
- step S22 the model 16 is sealed by sealing at each of the contact surfaces (15, 17) between the different model portions.
- This sealing is obtained by slightly locally melting the wax or the PMMA so as to bind the portions 12 and 14 to each other.
- the slip does not penetrate inside the model 16 (that is to say between the portions 12 and 14, and in contact of the core 10).
- the insert core 10 was entirely contained within the model 16. Alternatively, however, portions of the core 10 may also protrude outside the model 16, as illustrated by the appendixes 13 of the figure 7 . In this embodiment, the appendages 13 are provided to serve as anchorage for the core 10 in the shell mold produced subsequently.
- sealing connections 13a are provided between the portions of the model 16 and the core 10, plus particularly its appendages 13.
- the previously indicated sealing methods are also suitable for sealing the junctions between the model portions and the appendages 13.
- an expansion zone 18 may be provided so that there remains a clearance between the core 10 and the shell mold subsequently formed. Indeed, there may be a differential thermal expansion between the core 10 and the shell mold during the firing cycle of the shell mold containing the core and then the casting cycle of the parts, here blades. The expansion zone 18 and the resulting clearance ensures that the core 10 does not break under the effect of differential expansion.
- the model produced by the method according to the invention can be that of a part to be manufactured; but it may optionally include additional parts which are not part of the part to be manufactured and are eliminated during the finishing step (S7). Accordingly, the description and the drawings should be considered in an illustrative rather than restrictive sense.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
Description
L'invention concerne la fabrication de modèles de fonderie à modèle perdu. Par 'modèle de fonderie à modèle perdu' ou plus simplement 'modèle de fonderie' ou même 'modèle', on désigne ici une pièce réalisée au moins en partie en un matériau éliminable, et ayant sensiblement la même forme que la pièce que l'on cherche à fabriquer.The invention relates to the manufacture of investment casting patterns. By 'lost pattern foundry pattern' or more simply 'foundry pattern' or even 'pattern', here is meant a part made at least in part from an eliminable material, and having substantially the same shape as the part that the we are trying to make.
Le fait que le matériau soit éliminable signifie dans le présent contexte (d'un modèle de fonderie) que ce matériau est susceptible d'être éliminé sans détruire ou endommager le moule formé autour du modèle de fonderie. Cette élimination peut être faite par voie chimique (bains..), et/ou thermique, ou autre. Par exemple, le matériau éliminable peut être simplement un matériau fusible à basse température. L'expression 'fusible à basse température' signifie ici fusible à une température inférieure à 500°C, et de préférence inférieure à 100°C.The fact that the material is removable means in the present context (from a foundry pattern) that this material is capable of being removed without destroying or damaging the mold formed around the foundry pattern. This elimination can be done chemically (baths, etc.), and/or thermal, or other. For example, the removable material may simply be a low temperature fusible material. The expression 'low temperature fuse' here means fuse at a temperature below 500°C, and preferably below 100°C.
Un modèle peut inclure un ou plusieurs inserts, qui sont des pièces intégrées au modèle soit pour permettre la fabrication de celui-ci, soit pour faire partie de la pièce que l'on cherche à fabriquer.A model can include one or more inserts, which are parts integrated into the model either to allow the manufacture of the latter, or to form part of the part that one seeks to manufacture.
La fonderie à modèle perdu est un procédé connu comportant habituellement les étapes suivantes : on fabrique des modèles de fonderie ; on forme autour de ces modèles un moule carapace ; les modèles sont alors éliminés (à l'exception du ou des inserts éventuels) en chauffant le moule : les modèles fondent et/ou brûlent (à l'exception du ou des inserts éventuels) ; le matériau qui les constitue est alors évacué du moule. Le moule carapace est alors utilisé pour réaliser les pièces par fonderie.Investment casting is a known process usually comprising the following steps: casting patterns are produced; a shell mold is formed around these models; the models are then eliminated (with the exception of any insert(s)) by heating the mould: the models melt and/or burn (with the exception of any insert(s); the material which constitutes them is then evacuated from the mould. The shell mold is then used to make the parts by foundry.
L'invention concerne plus précisément la fabrication de modèles de fonderie à modèle perdu comportant un insert. De tels modèles servent soit à fabriquer des pièces qui incluent elles-mêmes un insert, soit à fabriquer des pièces creuses : dans ce dernier cas, l'insert du modèle de fonderie est un noyau, qui sert à aménager la partie creuse de la pièce lors de la coulée du métal en fusion, et est ensuite éliminé après refroidissement de la masse métallique.The invention relates more specifically to the manufacture of investment casting patterns comprising an insert. Such models are used either to manufacture parts which themselves include an insert, or to manufacture hollow parts: in the latter case, the insert of the foundry model is a core, which is used to arrange the hollow part of the part during the casting of the molten metal, and is then eliminated after the metal mass has cooled.
La fabrication de modèles de fonderie à modèle perdu se fait le plus souvent par injection-moulage. La fabrication d'un moule spécifique est donc nécessaire ; ce moule est généralement complexe.The manufacture of investment casting patterns is most often done by injection molding. The manufacture of a specific mold is therefore necessary; this mold is generally complex.
Aussi, comme il est ainsi nécessaire pour produire des modèles de concevoir et de faire réaliser un tel moule, la fabrication de modèles est coûteuse, en particulier pour de petites séries ; de plus, une durée relativement longue s'écoule entre le moment où la définition numérique du modèle à fabriquer est disponible, et le moment où le moule de fabrication de modèle est disponible pour permettre la fabrication des modèles. (Le terme « définition numérique » utilisé ci-dessus désigne le fichier numérique définissant la forme (en trois dimensions) d'une pièce, par exemple la forme d'un modèle à fabriquer. Ce fichier est habituellement obtenu à l'aide de logiciels de CAO tels que CATIA (marque déposée de la société DASSAULT SYSTEMES)).Also, as it is thus necessary to produce models to design and have such a mold made, the manufacture of models is expensive, in particular for small series; moreover, a relatively long time elapses between the moment when the digital definition of the model to be manufactured is available, and the moment when the model manufacturing mold is available to allow the manufacture of the models. (The term "digital definition" used above refers to the digital file defining the shape (in three dimensions) of a part, for example the shape of a model to be manufactured. This file is usually obtained using software CAD such as CATIA (registered trademark of the company DASSAULT SYSTEMES)).
Les documents
L'objectif de l'invention est donc de proposer un procédé de fabrication de modèles de fonderie, pour la fabrication de modèles de fonderie comportant un insert, plus rapide et moins cher que le procédé traditionnel exposé précédemment.The object of the invention is therefore to propose a process for the manufacture of foundry patterns, for the manufacture of foundry patterns comprising an insert, which is faster and less expensive than the traditional process described above.
Cet objectif est atteint grâce à un procédé de fabrication de modèle de fonderie à modèle perdu comportant les étapes suivantes :
- S1A) on fournit au moins un insert ;
- S1B) on fournit au moins deux portions du modèle, lesdites au moins deux portions étant réalisées dans un matériau éliminable ;
- S2) on fixe l'une à l'autre ou les unes aux autres de manière étanche lesdites au moins deux portions de modèle autour d'au moins une partie dudit au moins un insert de manière à réaliser ledit modèle.
- S1A) at least one insert is provided;
- S1B) at least two portions of the model are provided, said at least two portions being made of a removable material;
- S2) said at least two model portions are fixed to one another or to each other in a sealed manner around at least a part of said at least one insert so as to produce said model.
Le ou les insert(s) peuvent notamment comporter un noyau, prévu pour être éliminé après l'étape de coulée lors de la fonderie à modèle perdu. Ce ou ces noyaux peuvent être en particulier un ou des noyau(x) en céramique. Un ou plusieurs insert(s) peu(ven)t être également des inserts permanents, prévus pour être intégré à la pièce par exemple pour renforcer celle-ci mécaniquement.The insert(s) may in particular comprise a core, intended to be removed after the casting step during investment casting. This or these cores may in particular be one or more ceramic cores. One or more insert(s) can also be permanent inserts, intended to be integrated into the part, for example to reinforce it mechanically.
La réunion desdites au moins deux portions forme le modèle. Par conséquent, la forme du modèle est la réunion des formes (ou des volumes) des différentes portions.The joining of said at least two portions forms the model. Therefore, the shape of the model is the meeting of the shapes (or volumes) of the different portions.
Du fait que le modèle de fonderie est réalisé par assemblage de plusieurs portions de modèle, le procédé ci-dessous donne une grande souplesse accrue, par rapport au procédé traditionnel par injection-moulage dans un moule.Because the foundry pattern is made by assembling several portions of the pattern, the process below gives great increased flexibility, compared to the traditional process by injection molding in a mould.
En effet, les différentes portions du modèle sont plus simples à fabriquer, chacune, que le modèle lui-même ; notamment, parce que ces portions ne comportent pas d'insert. Avantageusement, il est donc possible de fabriquer ces portions de modèle par des procédés ne nécessitant pas l'utilisation d'outillages spécifiques.Indeed, the different portions of the model are easier to manufacture, each, than the model itself; in particular, because these portions do not include an insert. Advantageously, it is therefore possible to manufacture these model portions by methods that do not require the use of specific tools.
En particulier, l'étape S1B) de fabrication d'une ou de plusieurs des portions de modèle peut être faite en fabriquant une ou plusieurs desdites portions du modèle par un procédé additif. Elle peut également être faite par injection. Elle peut également être faite par tout autre procédé convenant à la fabrication d'une portion de modèle.In particular, step S1B) of manufacturing one or more of the model portions can be performed by manufacturing one or more of said model portions by an additive process. It can also be done by injection. It can also be made by any other process suitable for the manufacture of a model portion.
Il en va de même pour la fabrication du ou des inserts : l'étape S1A) de fourniture du ou des insert(s) peut être faite en fabriquant le ou les insert(s) par un procédé additif, par injection ou encore par tout autre procédé adapté.The same applies to the manufacture of the insert(s): step S1A) of supplying the insert(s) can be carried out by manufacturing the insert(s) by an additive process, by injection or by any another suitable method.
La réalisation du modèle par assemblage de ses portions autour du ou des inserts, à l'étape S2), nécessite toutefois de prendre certaines précautions.The production of the model by assembling its portions around the insert or inserts, in step S2), however, requires certain precautions to be taken.
En particulier, il faut exclure toute infiltration à l'intérieur du modèle (c'est-à-dire, entre un insert et une portion de modèle) du matériau servant à constituer le moule carapace.In particular, it is necessary to exclude any infiltration inside the model (that is to say, between an insert and a portion of the model) of the material used to constitute the shell mould.
Comme la fabrication du moule carapace à l'aide du modèle se fait en immergeant celui-ci dans une barbotine, on comprend que cela nécessite que le modèle de fonderie présente une étanchéité parfaite, c'est-à-dire que la barbotine ne puisse pas pénétrer entre les portions du modèle au contact de l'insert. En d'autres termes, on entend par « étanche » le fait que les zones de raccordement entre les portions de modèle et l'insert et/ou entre les portions de modèle entre elles ne laissent passer aucun corps étranger, au même titre que les parties utiles du reste du modèle.As the manufacture of the shell mold using the model is done by immersing it in a slip, it is understood that this requires that the foundry model has a perfect seal, that is to say that the slip cannot not penetrate between the portions of the model in contact with the insert. In other words, the term "tight" means the fact that the connection zones between the model portions and the insert and/or between the model portions between them do not allow any foreign body to pass, in the same way as the useful parts of the rest of the model.
C'est dans ce but qu'à l'étape S2, « on fixe l'une à l'autre ou les unes aux autres de manière étanche lesdites au moins deux portions de modèle autour d'au moins une partie dudit au moins un insert». Dans certains modes de réalisation, on assemble ainsi lesdites au moins deux portions de modèle de manière étanche autour de l'insert entier. Ainsi, le ou les insert(s) ne dépasse(nt) pas à l'extérieur du modèle : ils sont strictement contenus à l'intérieur de celui-ci et séparés de manière étanche de l'espace extérieur au modèle. Dans d'autres modes de réalisation, les portions de modèle sont assemblées de manière étanche autour seulement d'une partie de l'insert. Ainsi, après la mise en place de la ou des portions de modèle, le ou les inserts peuvent dépasser à l'extérieur du modèle ; les parties des inserts qui dépassent sont appelées appendices. Dans ces modes de réalisation, on s'assure alors que les portions de modèles sont assemblées de manière étanche autour des appendices. Pour ce faire, il est possible d'effectuer une reprise d'étanchéité des au moins deux portions de modèle, par exemple à l'aide d'un petit fer chauffant. Ces appendices du ou des inserts dépassant du ou des portions de modèles peuvent s'avérer utiles au processus de moulage, en particulier pour l'ancrage de l'insert dans la carapace, par exemple pour le respect des épaisseurs de paroi sur la pièce finale ou pour le maintien et contrôle dimensionnel de la cavité creuse.It is for this purpose that in step S2, "the said at least two model portions are fixed to one another or to each other in a sealed manner around at least a part of the said at least one insert”. In certain embodiments, said at least two model portions are thus assembled in a sealed manner around the entire insert. Thus, the insert(s) do not protrude outside the model: they are strictly contained inside the latter and separated in a sealed manner from the space outside the model. In other embodiments, the model portions are assembled in a sealed manner around only part of the insert. Thus, after the placement of the model portion(s), the insert(s) may protrude outside the model; the parts of the inserts that protrude are called appendages. In these embodiments, it is then ensured that the model portions are assembled in a sealed manner around the appendages. To do this, it is possible to carry out a re-sealing of the at least two portions of the model, for example using a small heating iron. These appendages of the insert(s) protruding from the model portion(s) may prove useful in the molding process, in particular for anchoring the insert in the shell, for example for respecting the wall thicknesses on the final part. or for the maintenance and dimensional control of the hollow cavity.
Cela étant, on comprend que le modèle est rendu étanche naturellement à l'exception de passages d'alimentation ou d'évacuation de matière prévus pour le procédé de fonderie à modèle perdu.This being the case, it is understood that the pattern is naturally sealed with the exception of passages for supplying or discharging material provided for the investment casting process.
Or il s'est avéré que, comme les différentes portions du modèle de fonderie sont généralement en matériau thermofusible, on peut utiliser localement les propriétés de fusion de ce matériau pour rendre étanche le modèle de fonderie au cours de l'étape de fabrication S2). Naturellement, tout autre procédé adapté pour rendre ce modèle étanche au cours de l'étape S2) peut être utilisé (notamment par ajout de résine d'étanchéité ou autre), en particulier si les portions de modèle ne sont pas réalisées en matériau thermofusible.However, it turned out that, as the different portions of the foundry pattern are generally made of thermofusible material, the melting properties of this material can be used locally to seal the foundry pattern during the manufacturing step S2) . Naturally, any other method suitable for making this model leaktight during step S2) can be used (in particular by adding sealing resin or the like), in particular if the model portions are not made of thermofusible material.
Grâce à cette précaution consistant à rendre étanche le modèle fabriqué par assemblage des portions de modèle, le modèle obtenu à l'issue de l'étape S2) permet son utilisation comme modèle de fonderie et permet notamment la fabrication d'un moule carapace.Thanks to this precaution consisting in sealing the model manufactured by assembling the model portions, the model obtained at the end of step S2) allows its use as a foundry model and in particular allows the manufacture of a shell mold.
Dans un mode préféré de mise en oeuvre, l'étape S2) du procédé comporte deux sous-étapes :
- S21) on assemble lesdites au moins deux portions de modèle autour de ladite au moins une partie dudit au moins un insert par collage ou par soudage ; puis
- S22) on rend étanche le modèle ainsi réalisé.
- S21) said at least two model portions are assembled around said at least a part of said at least one insert by gluing or by welding; Then
- S22) the model thus produced is sealed.
Le procédé est applicable en particulier à la fabrication de modèles de fonderie comportant un profil aérodynamique.The method is applicable in particular to the manufacture of foundry models comprising an aerodynamic profile.
Le procédé est applicable en particulier à la fabrication de modèles de fonderie comportant une pale.The method is applicable in particular to the manufacture of foundry models comprising a blade.
Dans ce dernier cas, dans un mode préféré de mise en oeuvre du procédé, à l'étape S1B), on fournit exactement deux portions du modèle, une portion d'intrados incluant la partie de la pale située du côté de l'intrados, et une portion d'extrados incluant la partie de la pale située du côté de l'extrados.In the latter case, in a preferred embodiment of the method, in step S1B), exactly two portions of the model are provided, an underside portion including the part of the blade located on the underside side, and an extrados portion including the part of the blade situated on the side of the extrados.
L'invention concerne également un procédé de fabrication d'une pièce en fonderie à modèle perdu, dans lequel un modèle est fabriqué par le procédé présenté précédemment.The invention also relates to a method of manufacturing a part in investment casting, in which a model is manufactured by the method presented previously.
L'invention sera bien comprise et ses avantages apparaîtront mieux à la lecture de la description détaillée qui suit, de modes de réalisation représentés à titre d'exemples non limitatifs. La description se réfère aux dessins annexés, sur lesquels :
- la
figure 1 est une vue schématique d'un procédé de fabrication d'aubes, constituant un mode de mise en oeuvre de l'invention ; - la
figure 2 est une vue en perspective schématique d'une grappe de modèles d'aubes obtenue lors de la mise en oeuvre du procédé présenté par lafigure 1 ; - la
figure 3 est une vue schématique en perspective d'un modèle d'aubes utilisé lors de la mise en oeuvre du procédé présenté par lafigure 1 ; - la
figure 4 est une vue schématique en éclaté en perspective du modèle d'aubes présenté par lafigure 3 ; - la
figure 5 est une vue schématique en coupe du modèle d'aubes présenté par lafigure 3 ; - la
figure 6 est une vue schématique en perspective de la coupe de modèle d'aubes présentée par lafigure 5 ; et - la
figure 7 est une vue schématique en perspective d'un modèle comprenant un insert présentant des appendices.
- there
figure 1 is a schematic view of a method of manufacturing blades, constituting an embodiment of the invention; - there
figure 2 is a schematic perspective view of a cluster of blade models obtained during the implementation of the method presented by thefigure 1 ; - there
picture 3 is a schematic perspective view of a model of blades used during the implementation of the method presented by thefigure 1 ; - there
figure 4 is a schematic exploded view in perspective of the blade model presented by thepicture 3 ; - there
figure 5 is a schematic sectional view of the blade model presented by thepicture 3 ; - there
figure 6 is a schematic perspective view of the blade model section presented by thefigure 5 ; And - there
figure 7 is a schematic perspective view of a model comprising an insert having appendages.
Le procédé de fabrication d'aubes présenté sur la
A titre d'exemple non limitatif, le procédé est présenté dans le cadre de la fabrication d'une grappe de douze aubes pour turbomachine.By way of non-limiting example, the method is presented in the context of the manufacture of a cluster of twelve blades for a turbomachine.
Le procédé comporte sept étapes S1 à S7. Les étapes S1 et S2 sont identiques pour chacune des douze aubes. Elles vont donc être décrites dans le cadre d'une aube (unique) ; il y a lieu en pratique de réaliser ces étapes pour chacune des douze aubes.The method comprises seven steps S1 to S7. Steps S1 and S2 are identical for each of the twelve blades. They will therefore be described in the context of a (single) blade; it is necessary in practice to carry out these steps for each of the twelve blades.
Cette étape S1 comporte deux opérations à réaliser en parallèle :
- au cours d'une étape S1A on fabrique un noyau (10) ;
- au cours d'une étape S1B on fabrique les portions (12, 14) du modèle.
- during a step S1A, a core (10) is manufactured;
- during a step S1B, the portions (12, 14) of the model are produced.
En général, on dispose de la définition numérique de la pièce à fabriquer.In general, we have the numerical definition of the part to be manufactured.
Pour la mise en oeuvre du procédé, il est donc nécessaire de définir les portions de modèle, à partir de la définition numérique de la pièce.For the implementation of the method, it is therefore necessary to define the model portions, from the digital definition of the part.
Cette opération peut être faite par tout moyen.This operation can be done by any means.
Une méthode consiste à créer les définitions numériques des portions du modèle à partir de la définition numérique de la pièce. Dans ce but, on divise la pièce en plusieurs portions.One method is to create the digital definitions of the portions of the model from the digital definition of the part. For this purpose, the room is divided into several portions.
Par exemple, si la pièce comporte une pale (comme c'est le cas dans l'exemple présenté) la pièce peut être divisée en une portion d'extrados 12 incluant la partie de la pale située du côté de l'extrados, et une portion d'intrados 14 incluant la partie de la pale située du côté de l'intrados.For example, if the part includes a blade (as is the case in the example presented) the part can be divided into an
Le modèle 16 est alors la réunion de deux portions, une portion d'intrados 14 et une portion d'extrados 12, qui correspondent aux parties de l'aube situées respectivement du côté de l'intrados et du côté de l'extrados (
Les portions de modèle peuvent être définies avec des zones de jonction présentant des complémentarités de forme (cônes, marches d'escalier, etc.). Ces complémentarités de forme servent, lors de l'assemblage des portions de modèle, à assurer le bon positionnement relatif des différentes portions du modèle, ce qui est important pour assurer que le modèle obtenu ait la forme la plus proche possible de celle spécifiée par la définition numérique de la pièce.The model portions can be defined with junction zones presenting shape complementarities (cones, stair steps, etc.). These shape complementarities are used, when assembling the model portions, to ensure the correct relative positioning of the different model portions, which is important to ensure that the resulting model has the shape as close as possible to that specified by the digital definition of the part.
Les portions de modèle peuvent de plus être définies avec des évidements et/ou des logements, prévus pour coopérer avec des parties correspondantes du noyau, de telle sorte que le noyau soit précisément maintenu en position par les portions d'aube à l'intérieur du modèle d'aube.The model portions can further be defined with recesses and/or housings, provided to cooperate with corresponding parts of the core, so that the core is precisely held in position by the blade portions inside the dawn pattern.
Une fois obtenues les définitions numériques des différentes portions choisies pour former le modèle, ces portions de modèle peuvent être fabriquées.Once the digital definitions of the various portions chosen to form the model have been obtained, these model portions can be manufactured.
Tout procédé peut être utilisé dans ce but.Any process can be used for this purpose.
Cependant, du fait que la définition numérique est disponible, on peut notamment fabriquer une ou plusieurs des portions de modèle par un procédé additif. Divers procédés de prototypage rapide peuvent être utilisés.However, because the digital definition is available, it is possible in particular to manufacture one or more of the model portions by an additive process. Various rapid prototyping methods can be used.
Le noyau 10 peut également être réalisé par un procédé additif, ou encore de manière classique par injection/cuisson.The core 10 can also be produced by an additive process, or even conventionally by injection/firing.
Les matériaux et les procédés de fabrication respectivement des portions de modèle et du noyau doivent être sélectionnés de telle sorte que :
- Les portions de modèle puissent être éliminées par chauffage ou autre sans laisser de résidus indésirables comme des suies ou des traces carbonées (lors de l'étape S5 décrite ci-après) ; et que
- Le noyau puisse résister aux contraintes thermiques appliquées lors de la coulée de la grappe d'aubes et puisse être éliminé par bain chimique sans laisser de résidus indésirables (lors de l'étape S6 décrite ci-après).
- The model portions can be removed by heating or the like without leaving undesirable residues such as soot or carbonaceous traces (during step S5 described below); and
- The core can withstand the thermal stresses applied during casting of the blade cluster and can be eliminated by chemical bath without leaving undesirable residues (during step S6 described below).
D'autres procédés que le chauffage sont envisageables pour l'élimination des portions de modèle. Par exemple, l'élimination peut être par voie chimique, par déliantage hypercritique, etc.Methods other than heating can be envisaged for the elimination of model portions. For example, the removal can be chemically, by hypercritical debinding, etc.
La fabrication d'un modèle d'aube 16 se fait en deux étapes successives :
- Au cours d'une première sous-étape 521 on assemble les deux portions de modèle 12 et 14 autour du noyau 10 (en tant qu'insert), ce qui permet de constituer un modèle d'aube 16. On fixe alors les portions de modèle 12 et 14 l'une à l'autre par collage. Tout en restant dans le cadre de l'invention, d'autres procédés de fixation peuvent être utilisés, comme le soudage, l'assemblage mécanique par exemple par emboîtement et/ou vissage, etc.
- Au cours d'une deuxième sous-étape S22 on parachève le modèle 16 de telle sorte qu'il soit étanche à l'exception de passages d'alimentation ou d'évacuation de matière prévus pour le procédé de fonderie à modèle perdu.
- During a first sub-step 521, the two
12 and 14 are assembled around the core 10 (as an insert), which makes it possible to form amodel portions blade model 16. The 12 and 14 to each other by gluing. While remaining within the scope of the invention, other fastening methods can be used, such as welding, mechanical assembly, for example by interlocking and/or screwing, etc.model - During a second sub-step S22, the
pattern 16 is completed in such a way that it is sealed with the exception of material supply or evacuation passages provided for the investment casting process.
Lors de cette étape S3, on fabrique une grappe 20 de modèles en cire (
La grappe 20 est fabriquée en assemblant les modèles d'aubes 16 réalisés à l'étape S2 à l'aide d'éléments auxiliaires préfabriqués 22.The
Ces éléments auxiliaires 22 servent à former les parties techniques du moule carapace, notamment les canaux d'alimentation et d'évacuation de métal, les écrans thermiques, etc. Ils comportent notamment deux disques 24 parallèles, chacun de ces disques ayant la forme d'un plateau percé de trous par lesquels passent les modèles d'aubes 16.These
Les modèles d'aube 16 sont tous identiques les unes aux autres. Ils sont disposés en cercle de manière axisymétrique autour d'un axe X, dit axe de coulée. L'axe X est disposé suivant la direction verticale pendant l'opération de fonderie, lorsque du métal en fusion est coulé dans le moule carapace (opération présentée plus en détail ci-dessous).The 16 vane models are all identical to each other. They are arranged in a circle axisymmetrically around an X axis, called the casting axis. The X axis is arranged in the vertical direction during the foundry operation, when molten metal is poured into the shell mold (discussed in more detail below).
Lors de la fabrication du moule carapace, les modèles d'aubes 16 vont servir à aménager des cavités de moulage pour le moulage d'aubes ; les éléments auxiliaires 22 vont servir à aménager notamment un godet de coulée, des canaux d'amenée, des raidisseurs et des sélecteurs.During the manufacture of the shell mould, the
Dans l'étape S4, on fabrique le moule carapace en immergeant la grappe non permanente 20 dans une barbotine à partir de laquelle se forme la carapace (cette étape ainsi que les étapes ultérieures S5 à S7 sont décrites plus en détail par le document
Dans cette étape S5, on élimine les modèles d'aube en chauffant le moule carapace dans lequel se trouve la grappe non permanente. Sous l'effet de la chaleur, les modèles d'aube fondent et/ou brûlent, ce qui permet de les éliminer et de libérer le volume intérieur du moule carapace. On forme alors la grappe de pièces de fonderie - c'est-à-dire la grappe d'aubes, dans le moule carapace en coulant du métal en fusion dans celui-ci.In this step S5, the blade models are eliminated by heating the shell mold in which the non-permanent cluster is located. Under the effect of heat, the blade models melt and/or burn, which makes it possible to eliminate them and free the interior volume of the shell mould. The cluster of castings - that is to say the cluster of blades - is then formed in the shell mold by pouring molten metal into the latter.
Dans une sixième étape S6, après le refroidissement et la solidification du métal dans le moule carapace, les noyaux d'aubes sont éliminés par trempage dans un bain chimique basique, et la grappe d'aubes est décochée du moule carapace.In a sixth step S6, after cooling and solidification of the metal in the shell mould, the blade cores are removed by soaking in a basic chemical bath, and the cluster of blades is removed from the shell mould.
Enfin, dans une septième étape S7 chacune des aubes est séparée du reste de la grappe et finie par des procédés d'usinage et/ou des traitements de surface.Finally, in a seventh step S7 each of the blades is separated from the rest of the cluster and finished by machining processes and/or surface treatments.
Au sein du procédé de fabrication d'aube présenté précédemment, l'invention concerne plus particulièrement les étapes S1 et S2, c'est-à-dire la fabrication des modèles d'aubes 16. Un exemple de mise en oeuvre de ces étapes est illustré par les
Le modèle d'aube 16 est un modèle en cire d'une aube comportant une pale 30 et un pied 32.The
La
Les
L'aube que le modèle d'aube 16 sert à fabriquer est une aube creuse. Aussi, pour la fabrication de celle-ci par fonderie à modèle perdu, il est nécessaire d'utiliser un noyau - en l'occurrence le noyau 10. La forme du noyau 10 délimite le volume intérieur de l'aube que l'on cherche à maintenir vide, c'est-à-dire le volume intérieur de l'aube qui ne doit pas être rempli de métal lors de la fonderie.The blade that the
Les portions de modèle 12 et 14 sont dotées de saillies tronconiques 11, et le noyau 10 est doté de trous correspondants 11 de forme tronconique, qui permettent un maintien en position relative précis du noyau 10 par rapport aux portions de modèle 12 et 14.The
Le noyau 10 est réalisé séparément en céramique lors de l'étape S1A, de manière connue en soi (par exemple par moulage dans une boîte à noyaux, ou par fabrication additive par exemple par frittage de poudre). Il est constitué principalement de silice.
Son matériau est sélectionné de telle sorte que sa température de fusion soit supérieure à 1300°C. Grâce à cela, le noyau ne fond pas lors de l'étape S5 de coulée de la grappe d'aubes. Inversement, ce matériau est sélectionné de manière à pouvoir être éliminé par des solvants chimiques lors de l'étape S6.Its material is selected so that its melting temperature is above 1300°C. Thanks to this, the core does not melt during step S5 of casting the cluster of blades. Conversely, this material is selected so that it can be eliminated by chemical solvents during step S6.
Les portions de modèle 12 et 14 sont fabriquées séparément (étape S1B). Elles sont réalisées en matériau éliminable : dans le cas présent, en matériau fusible à basse température. Elles peuvent par exemple être fabriquées en prototypage rapide, par dépôt de filament de cire ou par frittage de poudre. Elles peuvent être réalisées par exemple en PMMA (polymétachrylate de méthyle) ou dans d'autres polymères organiques. Ces matériaux peuvent être éliminés en étant portés à une température de l'ordre de 1000°C dans une étuve de brûlage, lors de l'étape S5 avant la coulée du métal.
La forme des portions de modèle 12 et 14 est telle que la réunion de leurs volumes correspond sensiblement au volume de l'aube que l'on cherche à fabriquer.The shape of the
Les portions 12 et 14 sont en contact au niveau de deux surfaces de contact : une surface de contact amont 15 et une surface de contact aval 17. Ces surfaces sont définies de telle sorte que la réunion du noyau 10, des portions 12 et 14 se fasse aisément et sans difficultés liées à des contre-dépouilles ou autre.
Lors de l'étape S21, on dépose une mince couche de colle sur les surfaces de contact 15 et 17 ; on colle les portions 12 et 14 l'une à l'autre, le noyau 10 étant disposé entre celles-ci.During step S21, a thin layer of adhesive is deposited on the contact surfaces 15 and 17; the
Cette étape d'assemblage et de collage ne garantit cependant pas que le modèle 16 soit étanche.However, this assembly and gluing step does not guarantee that the
Aussi, au cours de l'étape S22, on rend le modèle 16 étanche en assurant l'étanchéité au niveau de chacune des surfaces de contact (15, 17) entre les différentes portions de modèle.Also, during step S22, the
Cette étanchéité est obtenue en faisant légèrement fondre localement la cire ou bien le PMMA de manière à lier l'une à l'autre les portions 12 et 14.This sealing is obtained by slightly locally melting the wax or the PMMA so as to bind the
Grâce à l'étanchéité ainsi réalisée, lors de l'opération S4 de fabrication du moule carapace, la barbotine ne pénètre pas à l'intérieur du modèle 16 (c'est-à-dire entre les portions 12 et 14, et au contact du noyau 10).Thanks to the tightness thus produced, during the shell mold manufacturing operation S4, the slip does not penetrate inside the model 16 (that is to say between the
Dans le précédent mode de réalisation, le noyau 10 formant insert était entièrement contenu dans le modèle 16. Toutefois, en variante, des parties du noyau 10 peut également dépasser à l'extérieur du modèle 16, comme illustré par les appendices 13 de la
Afin d'assurer l'étanchéité du modèle 16, des raccords d'étanchéité 13a sont ménagés entre les portions du modèle 16 et le noyau 10, plus particulièrement ses appendices 13. Les procédés d'étanchéisation précédemment indiqués conviennent également pour rendre étanches les jonctions entre les portions de modèle et les appendices 13.In order to ensure the tightness of the
En outre, comme représenté sur la
Quoique la présente invention ait été décrite en se référant à des exemples de réalisation spécifiques, il est évident que des différentes modifications et changements peuvent être effectués sur ces exemples sans sortir de la portée générale de l'invention telle que définie par les revendications. En outre, des caractéristiques individuelles des différents modes de réalisation évoqués peuvent être combinées dans des modes de réalisation additionnels. Par exemple, le modèle réalisé par le procédé selon l'invention peut être celui d'une pièce à fabriquer ; mais il peut éventuellement inclure des parties supplémentaires qui ne font pas partie de la pièce à fabriquer et sont éliminées lors de l'étape de finition (S7). 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 various modifications and changes can be made to these examples without departing from the general scope of the invention as defined by the claims. Further, individual features of the various embodiments discussed may be combined in additional embodiments. For example, the model produced by the method according to the invention can be that of a part to be manufactured; but it may optionally include additional parts which are not part of the part to be manufactured and are eliminated during the finishing step (S7). Accordingly, the description and the drawings should be considered in an illustrative rather than restrictive sense.
Claims (8)
- A fabrication method for fabricating a pattern for lost pattern casting, the method comprising the following steps:S1A) providing at least one insert (10);S1B) providing at least two pattern portions (12, 14), said at least two portions being made of a material that can be eliminated; andS2) assembling said at least two pattern portions together around at least a portion of said at least one insert in sealed manner so as to make said pattern (16).
- A fabrication method according to claim 1, wherein said at least one insert comprises a core (10) designed to be eliminated after the casting step (S5) during lost pattern casting.
- A fabrication method according to claim 1 or claim 2, wherein step S1B) is performed by fabricating at least one of said portions (12, 14) of the pattern by an additive method or by injection molding.
- A fabrication method according to any one of claims 1 to 3, wherein step S1A) is performed by fabricating said at least one insert (10) by an additive method or by injection molding.
- A fabrication method according to any one of claims 1 to 4, wherein the pattern includes an airfoil (30).
- A fabrication method according to claim 5, wherein, in step S1B), exactly two portions of the pattern are provided, a suction side portion (12) including the portion of the airfoil that is situated on the suction side, and a pressure side portion (14) including the portion of the airfoil situated on the pressure side.
- A fabrication method according to any one of claims 1 to 6, wherein step S2) comprises two substeps:S21) assembling said at least two pattern portions (12, 14) around said at least one portion of said at least one insert (10) by adhesive or by welding; andS22) sealing the pattern as made in this way.
- A method of fabricating an lost pattern casting, wherein a pattern (16) is fabricated by the method according to any one of claims 1 to 7.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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FR1553937A FR3035604B1 (en) | 2015-04-30 | 2015-04-30 | PATTERN MANUFACTURING PROCESS FOR LOST PATTERN FOUNDRY |
PCT/FR2016/050980 WO2016174344A1 (en) | 2015-04-30 | 2016-04-26 | Method for producing a pattern for investment casting |
Publications (2)
Publication Number | Publication Date |
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EP3288699A1 EP3288699A1 (en) | 2018-03-07 |
EP3288699B1 true EP3288699B1 (en) | 2023-08-02 |
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EP16722312.2A Active EP3288699B1 (en) | 2015-04-30 | 2016-04-26 | Method for producing a pattern for investment casting |
Country Status (5)
Country | Link |
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US (1) | US10913105B2 (en) |
EP (1) | EP3288699B1 (en) |
CN (1) | CN107645974A (en) |
FR (1) | FR3035604B1 (en) |
WO (1) | WO2016174344A1 (en) |
Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3981344A (en) * | 1974-08-21 | 1976-09-21 | United Technologies Corporation | Investment casting mold and process |
Family Cites Families (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB939328A (en) * | 1961-01-27 | 1963-10-09 | Howe Sound Co | Apparatus and method for the production of cored patterns |
GB2150874B (en) * | 1983-12-07 | 1986-07-09 | Rolls Royce | Investment casting |
US5465780A (en) * | 1993-11-23 | 1995-11-14 | Alliedsignal Inc. | Laser machining of ceramic cores |
DE10038453A1 (en) * | 2000-08-07 | 2002-02-21 | Alstom Power Nv | Production of a cooled cast part of a thermal turbo machine comprises applying a wax seal to an offset between a wax model a core before producing the casting mold, the offset being located above the step to the side of the core. |
WO2002049824A1 (en) * | 2000-12-19 | 2002-06-27 | Pcc Structurals, Inc. | Casting pattern seam tool and method for its use |
EP1930096A1 (en) * | 2006-12-07 | 2008-06-11 | Siemens Aktiengesellschaft | Methof of manufacturing casting pattern for investment casting of parts containing at least one hollow portion |
US7674093B2 (en) | 2006-12-19 | 2010-03-09 | General Electric Company | Cluster bridged casting core |
US7942188B2 (en) * | 2008-03-12 | 2011-05-17 | Vent-Tek Designs, Llc | Refractory metal core |
FR2995807B1 (en) | 2012-09-25 | 2015-10-09 | Snecma | THERMAL SCREEN CARAPLE MOLD |
-
2015
- 2015-04-30 FR FR1553937A patent/FR3035604B1/en active Active
-
2016
- 2016-04-26 CN CN201680026737.8A patent/CN107645974A/en active Pending
- 2016-04-26 WO PCT/FR2016/050980 patent/WO2016174344A1/en active Application Filing
- 2016-04-26 EP EP16722312.2A patent/EP3288699B1/en active Active
- 2016-04-26 US US15/570,011 patent/US10913105B2/en active Active
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3981344A (en) * | 1974-08-21 | 1976-09-21 | United Technologies Corporation | Investment casting mold and process |
Also Published As
Publication number | Publication date |
---|---|
EP3288699A1 (en) | 2018-03-07 |
CN107645974A (en) | 2018-01-30 |
FR3035604A1 (en) | 2016-11-04 |
US10913105B2 (en) | 2021-02-09 |
FR3035604B1 (en) | 2023-01-13 |
WO2016174344A1 (en) | 2016-11-03 |
US20180154427A1 (en) | 2018-06-07 |
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