EP0409726A1 - Method for fabricating foundry shell moulds - Google Patents
Method for fabricating foundry shell moulds Download PDFInfo
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- EP0409726A1 EP0409726A1 EP90402066A EP90402066A EP0409726A1 EP 0409726 A1 EP0409726 A1 EP 0409726A1 EP 90402066 A EP90402066 A EP 90402066A EP 90402066 A EP90402066 A EP 90402066A EP 0409726 A1 EP0409726 A1 EP 0409726A1
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- model
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- drying
- solution
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- 238000000034 method Methods 0.000 title claims abstract description 29
- 239000000919 ceramic Substances 0.000 claims abstract description 21
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 18
- 239000002904 solvent Substances 0.000 claims abstract description 13
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims abstract description 12
- 230000008021 deposition Effects 0.000 claims abstract description 11
- FZHAPNGMFPVSLP-UHFFFAOYSA-N silanamine Chemical compound [SiH3]N FZHAPNGMFPVSLP-UHFFFAOYSA-N 0.000 claims abstract description 7
- 238000001035 drying Methods 0.000 claims description 14
- 239000000725 suspension Substances 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 11
- 239000012530 fluid Substances 0.000 claims description 10
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 claims description 9
- 238000003379 elimination reaction Methods 0.000 claims description 8
- 230000008030 elimination Effects 0.000 claims description 7
- 238000007654 immersion Methods 0.000 claims description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000007767 bonding agent Substances 0.000 claims description 3
- 238000007596 consolidation process Methods 0.000 claims description 3
- 238000001704 evaporation Methods 0.000 claims description 3
- 230000008020 evaporation Effects 0.000 claims description 3
- 238000002156 mixing Methods 0.000 claims description 3
- 238000010438 heat treatment Methods 0.000 claims description 2
- 238000005245 sintering Methods 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 239000002689 soil Substances 0.000 claims 1
- QTBSBXVTEAMEQO-UHFFFAOYSA-M Acetate Chemical compound CC([O-])=O QTBSBXVTEAMEQO-UHFFFAOYSA-M 0.000 abstract description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 abstract 2
- 238000000926 separation method Methods 0.000 abstract 1
- 238000000151 deposition Methods 0.000 description 13
- 239000001993 wax Substances 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 3
- 238000007792 addition Methods 0.000 description 3
- 238000002791 soaking Methods 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- IGFHQQFPSIBGKE-UHFFFAOYSA-N Nonylphenol Natural products CCCCCCCCCC1=CC=C(O)C=C1 IGFHQQFPSIBGKE-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- 239000002318 adhesion promoter Substances 0.000 description 1
- 229920013820 alkyl cellulose Polymers 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 230000003254 anti-foaming effect Effects 0.000 description 1
- 239000007900 aqueous suspension Substances 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000001687 destabilization Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 238000005187 foaming Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- SNQQPOLDUKLAAF-UHFFFAOYSA-N nonylphenol Chemical compound CCCCCCCCCC1=CC=CC=C1O SNQQPOLDUKLAAF-UHFFFAOYSA-N 0.000 description 1
- 230000007420 reactivation Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 238000004513 sizing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
Classifications
-
- 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
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S264/00—Plastic and nonmetallic article shaping or treating: processes
- Y10S264/57—Processes of forming layered products
Definitions
- the present invention relates to a process for manufacturing shell molds for foundries, in particular intended for use in so-called lost wax foundry processes.
- the lost-wax foundry processes using ceramic shell molds include the following steps: - production of a model, generally in wax, of the part to be produced, - deposit on the model of a ceramic suspension from a thick slip, - deposit of ceramic grains in stucco, - drying, for example in an oven, leading to elimination of the solvent from the suspension and consolidation of the layer, - depositing a new layer of ceramic suspension from a fluid slip, - new deposition of ceramic grains in stucco, - drying, as before, the layers are optionally renewed as many times as new elements must be introduced in order to obtain the characteristics sought in the particular application, whether they are of a physical, chemical or mechanical nature, - heat treatment of the assembly obtained under determined conditions, adapted to the compositions and products used, leading to the elimination of the organic model and to a "baking" of the mold with consolidation in particular by possibly reactive sintering, - Carrying out a part casting operation in the mold obtained.
- slip composition examples are in particular given by FR-A-2 599 649.
- compositions of the slip have been added, such as those based on nonylphenol.
- surfactants have been added, such as those based on nonylphenol.
- these additions involve a risk of destabilization of the compositions and usually have a foaming effect which requires an additional addition of an anti-foaming product.
- the film is obtained from a solution of alkyl cellulose, wetting agent, formaldehyde and ammonium hydroxide in water.
- a solvent product was prepared by mixing ethanol and ethyl acetate. Tests carried out using various proportions of the components have made it possible to establish that the acceptable proportions of each of the constituents are between 25% and 75%. In particular, it has been found that alcohol alone reacts with the adhesion agent used and makes it ineffective in less than 24 hours. Furthermore, ethyl acetate alone leads to a deterioration in the surface condition of the wax model by dissolution. On the other hand, the mixture of the two products in the proportions indicated limits the harmful reactions.
- a solution is obtained by adding to said solvent 3% of an adhesion agent of the aminosilane type.
- an adhesion agent of the aminosilane type Various commercial products supplied by the Dynamit Nobel Company under the trade names Dynasilan 1505 or Ammo, for example, have been successfully tested.
- the solution obtained has good stability and has a shelf life in closed containers of several weeks.
- step (b) of depositing a layer of ceramic suspension was carried out by dipping the model in a fluid slip, followed by step (c) of drying.
- step b of the method according to the invention makes it possible to better coat the model in the locked up or inaccessible areas during the soaking operations and to better control the thicknesses deposited at draining.
- the stucco grains are attached to a second layer reinforcing the first dry layer resulting from the fluid slip, which prevents the stucco from passing through the first layer, coming into contact with the wax of the model and deteriorating the surface condition. Whatever the stucco used, fine or coarse, an improvement of around 30% of Ra was thus observed in the surface condition of the shell obtained.
- the effectiveness of the adhesion agent was tested on various waxes and on a rhodoid-type model material.
- the mode of application of the solution comprising the adhesion agent which has been described by immersion can be carried out by spraying.
- the adhesion agent can be obtained from an aminosilane type product.
- the conventional process using a thick slip can be preserved by incorporating the prior step of depositing the adhesion agent, in accordance with the invention and by retaining the advantages of improving the sizing at the wax / ceramic interface and avoiding subsequent decohesions, especially in the case of overdrying.
Abstract
Description
La présente invention concerne un procédé de fabrication de moules-carapaces pour fonderie, notamment destinés à être utilisés dans des procédés de fonderie dits à la cire perdue.The present invention relates to a process for manufacturing shell molds for foundries, in particular intended for use in so-called lost wax foundry processes.
Comme il est déjà bien connu, les procédés de fonderie à la cire perdue utilisant des moules-carapaces en céramique comportent notamment les étapes suivantes :
- réalisation d'un modèle, généralement en cire, de la pièce à réaliser,
- dépôt sur le modèle d'une suspension de céramiques à partir d'une barbotine épaisse,
- dépôt de grains de céramique en stucco,
- séchage, par exemple en étuve, entraînant une élimination du solvant de la suspension et une consolidation de la couche,
- dépôt d'une nouvelle couche de suspension de céramiques à partir d'une barbotine fluide,
- nouveau dépôt de grains de céramique en stucco,
- séchage, comme précédemment,
- les couches sont renouvelées éventuellement autant de fois que de nouveaux éléments doivent être introduits en vue d'obtenir les caractéristiques recherchées dans l'application particulière, qu'elles soient de nature physique, chimique ou mécanique,
- traitement thermique de l'ensemble obtenu dans des conditions déterminées, adaptées aux compositions et produits utilisés, conduisant à l'élimination du modèle organique et à une "cuisson" du moule avec une consolidation notamment par frittage éventuellement réactif,
- réalisation d'une opération de coulée de pièce dans le moule obtenu.As is already well known, the lost-wax foundry processes using ceramic shell molds include the following steps:
- production of a model, generally in wax, of the part to be produced,
- deposit on the model of a ceramic suspension from a thick slip,
- deposit of ceramic grains in stucco,
- drying, for example in an oven, leading to elimination of the solvent from the suspension and consolidation of the layer,
- depositing a new layer of ceramic suspension from a fluid slip,
- new deposition of ceramic grains in stucco,
- drying, as before,
the layers are optionally renewed as many times as new elements must be introduced in order to obtain the characteristics sought in the particular application, whether they are of a physical, chemical or mechanical nature,
- heat treatment of the assembly obtained under determined conditions, adapted to the compositions and products used, leading to the elimination of the organic model and to a "baking" of the mold with consolidation in particular by possibly reactive sintering,
- Carrying out a part casting operation in the mold obtained.
Des exemples de composition de barbotine sont notamment donnés par FR-A-2 599 649.Examples of slip composition are in particular given by FR-A-2 599 649.
Dans l'utilisation d'un procédé tel qu'il a été schématiquement décrit ci-dessus diverses difficultés sont apparues imposant des précautions particulières d'emploi. Le dépôt de la première couche sur le modèle en cire s'avère notamment délicat. Il est nécessaire en effet d'utiliser une barbotine épaisse pour obtenir cette première couche, de la revêtir d'un dépôt de grains et de surveiller de près les conditions de séchage pour éviter un surséchage. Toutes ces conditions contraignantes sont en effet nécessaires pour limiter les décohésions de ladite première couche et éviter un phénomène de feuilletage. Ces difficultés sont aggravées notamment lorsque le modèle présente des zones peu accessibles dites "enfermées" et des problèmes d'adhérence du dépôt céramique sur le modèle en cire entraînant des décollements de la couche apparaissent également en présence d'angles vifs ou de sections fines. Ces configurations sont notamment rencontrées dans des applications particulièrement visées par l'invention à des pièces aéronautiques, notamment destinées à des moteurs aéronautiques, et qui présentent ces particularités, comme par exemple des aubes refroidies pour turbines.In the use of a process as it has been schematically described above, various difficulties have arisen imposing special precautions for use. The deposition of the first layer on the wax model is particularly delicate. It is indeed necessary to use a thick slip to obtain this first layer, to coat it with a grain deposit and to closely monitor the drying conditions to avoid overdrying. All these restrictive conditions are in fact necessary to limit the decohesions of said first layer and to avoid a lamination phenomenon. These difficulties are aggravated in particular when the model has inaccessible areas called "enclosed" and problems of adhesion of the ceramic deposit on the wax model causing detachments of the layer also appear in the presence of sharp angles or fine sections. These configurations are notably encountered in applications particularly targeted by the invention in aeronautical parts, in particular intended for aeronautical engines, and which have these characteristics, such as, for example, cooled blades for turbines.
Certaines tentatives de solution ont consisté notamment à rechercher des ajustements de compositions des barbotines. C'est ainsi que, notamment dans le cas de compositions d'un type connu en soi comportant un liant colloïdal, des produits tensio-actifs ont été rajoutés, tels que à base de nonylphénol. Toutefois ces rajouts comportent un risque de déstabilisation des compositions et ont habituellement un effet moussant qui impose un ajout supplémentaire d'un produit anti-moussant.Certain attempts at solution have consisted in particular in seeking adjustments to the compositions of the slip. Thus, in particular in the case of compositions of a type known per se comprising a colloidal binder, surfactants have been added, such as those based on nonylphenol. However, these additions involve a risk of destabilization of the compositions and usually have a foaming effect which requires an additional addition of an anti-foaming product.
On connaît également par US-A-2 908 952 le principe d'application d'un film d'adhérence et de protection sur un modèle pour réaliser un moule. Dans ce cas, le film est obtenu à partir d'une solution d'alkyl cellulose, agent mouillant, formaldéhyde et hydroxyde d'ammonium dans l'eau.We also know from US-A-2,908,952 the principle of applying an adhesion and protection film on a model to produce a mold. In this case, the film is obtained from a solution of alkyl cellulose, wetting agent, formaldehyde and ammonium hydroxide in water.
Ces problèmes ont été résolus grâce à l'invention sans entraîner les inconvénients des solutions précédemment connues et en procurant de nombreux avantages notamment par rapport au choix connu des produits utilisés pour l'adhérence, au moyen d'un procédé de fabrication de moules-carapaces pour fonderie du type précédemment évoqué comportant les étapes successives suivantes :
- (a) -dépôt sur le modèle d'un agent d'adhérence ;
- (b) dépôt d'une couche d'une suspension de céramiques à partir d'une barbotine fluide ;
- (c) -séchage ;
- (d) -dépôt d'une nouvelle couche de suspension de céramique à partir de la même barbotine fluide précédemment utilisée à l'étape (b) ;
- (e) -dépôt de grains de céramique en stucco ;
- (f) -séchage.
- (a) -deposit on the model of a bonding agent;
- (b) depositing a layer of a ceramic suspension from a fluid slip;
- (c) -drying;
- (d) -deposition of a new layer of ceramic suspension from the same fluid slip previously used in step (b);
- (e) -deposit of ceramic grains in stucco;
- (f) -drying.
D'autres caractéristiques et avantages de l'invention seront mieux compris à la lecture de la description qui va suivre d'un exemple non limitatif de réalisation illustrant l'invention.Other characteristics and advantages of the invention will be better understood on reading the description which follows of a nonlimiting embodiment illustrating the invention.
On a préparé un produit solvant par mélange d'éthanol et d'acétate d'éthyle. Les tests réalisés à partir de diverses proportions des composants ont permis d'établir que les proportions acceptables de chacun des constituants se situent entre 25% et 75%. On a notamment constaté que l'alcool seul avait une réaction avec l'agent d'adhérence utilisé et le rend inefficace en moins de 24 heures. Par ailleurs, l'acétate d'éthyle seul conduit à une détérioration de l'état de surface du modèle en cire par dissolution. Par contre le mélange des deux produits dans les proportions indiquées limitent les réactions néfastes.A solvent product was prepared by mixing ethanol and ethyl acetate. Tests carried out using various proportions of the components have made it possible to establish that the acceptable proportions of each of the constituents are between 25% and 75%. In particular, it has been found that alcohol alone reacts with the adhesion agent used and makes it ineffective in less than 24 hours. Furthermore, ethyl acetate alone leads to a deterioration in the surface condition of the wax model by dissolution. On the other hand, the mixture of the two products in the proportions indicated limits the harmful reactions.
Une solution est obtenue en ajoutant dans ledit solvant 3% d'un agent d'adhérence de type aminosilane. Divers produits commerciaux fournis par la Société Dynamit Nobel sous les dénominations commerciales Dynasilan 1505 ou Ammo, par exemple, ont été testés avec succès. La solution obtenue présente une bonne stabilité et a une durée de conservation en bidon fermé de plusieurs semaines.A solution is obtained by adding to said solvent 3% of an adhesion agent of the aminosilane type. Various commercial products supplied by the Dynamit Nobel Company under the trade names Dynasilan 1505 or Ammo, for example, have been successfully tested. The solution obtained has good stability and has a shelf life in closed containers of several weeks.
L'étape (a) du procédé de fabrication de moules-carapaces pour fonderie caractéristique de l'invention et consistant en un dépôt d'un agent d'adhérence sur le modèle peut alors être effectuée selon le processus suivant :
- (a1) -immersion du modèle dans la solution dont la préparation a été décrite ci-dessus, pendant 3 à 4 minutes au moins ;
- (a2) -élimination du solvant par évaporation à l'ambiante;
- (a3)-rinçage éventuel à l'eau pour éliminer les coulures éventuelles ou surplus d'agent d'adhérence ;
- (a4) -séchage à l'ambiante.
- (a1) -immersion of the model in the solution whose preparation has been described above, for at least 3 to 4 minutes;
- (a2) -elimination of the solvent by ambient evaporation;
- (a3) - possible rinsing with water to eliminate any drips or excess of adhesion agent;
- (a4) - ambient drying.
L'efficacité du dépôt d'agent d'adhérence ainsi obtenu sur le modèle est conservée pendant environ 24 heures et une réactivation reste possible, simplement en répétant le processus a1 à a4 décrit ci-dessus.The effectiveness of the deposit of adhesion agent thus obtained on the model is kept for approximately 24 hours and reactivation remains possible, simply by repeating the process a1 to a4 described above.
Après ce dépôt, on a procédé à l'étape (b) de dépôt d'une couche de suspension de céramique par trempage du modèle dans une barbotine fluide, suivie de l'étape (c) de séchage.After this deposition, step (b) of depositing a layer of ceramic suspension was carried out by dipping the model in a fluid slip, followed by step (c) of drying.
La suppression de l'utilisation précédemment mise en oeuvre dans les procédés antérieurs connus d'une barbotine épaisse pour la réalisation de la première couche présente divers avantages :
- du fait de sa densité, cette barbotine épaisse nécessitait l'utilisation d'un mélangeur particulier pour sa préparation ;
- sa stabilité est moins assurée et on rencontrait des difficultés à contrôler et maintenir constante cette barbotine épaisse du fait de l'évolution sensible dans le temps de ses caractéristiques rhéologiques et de son pH ;
- un procédé de trempage utilisant un robot ne lui était guère applicable, contrairement à la barbotine fluide utilisée selon l'invention.The elimination of the use previously implemented in the known prior processes of a thick slip for the production of the first layer has various advantages:
- because of its density, this thick slip required the use of a special mixer for its preparation;
- Its stability is less assured and we encountered difficulties in controlling and keeping constant this thick slip due to the significant evolution over time of its rheological characteristics and its pH;
- A soaking process using a robot was hardly applicable to him, unlike the fluid slip used according to the invention.
On a ensuite répété autant de fois que nécessaire pour obtenir les épaisseurs désirées et les caractéristiques du moule recherchées les étapes suivantes du procédé conforme à l'invention :
- - (d) dépôt d'une nouvelle couche de suspension de céramiques à partir de la même barbotine fluide utilisée à l'étape (b) ;
- - (e) dépôt de grains de céramique en stucco;
- - (f) séchage.
- - (d) depositing a new layer of ceramic suspension from the same fluid slip used in step (b);
- - (e) depositing ceramic grains in stucco;
- - (f) drying.
L'utilisation d'une barbotine fluide dès le premier trempage du modèle (étape b du procédé selon l'invention) permet de mieux napper le modèle dans les enfermés ou zones peu accessibles lors des opérations de trempage et de mieux maîtriser les épaisseurs déposées à l'égouttage. L'accrochage des grains en stucco est réalisé sur une seconde couche renforçant la première couche sèche issue de la barbotine fluide, ce qui empêche le stucco de traverser la première couche, d'entrer en contact avec la cire du modèle et de détériorer l'état de surface. Quel que soit le stucco utilisé, fin ou grossier, on a ainsi observé une amélioration, de l'ordre de 30% du Ra, de l'état de surface de la carapace obtenue.The use of a fluid slip from the first soaking of the model (step b of the method according to the invention) makes it possible to better coat the model in the locked up or inaccessible areas during the soaking operations and to better control the thicknesses deposited at draining. The stucco grains are attached to a second layer reinforcing the first dry layer resulting from the fluid slip, which prevents the stucco from passing through the first layer, coming into contact with the wax of the model and deteriorating the surface condition. Whatever the stucco used, fine or coarse, an improvement of around 30% of Ra was thus observed in the surface condition of the shell obtained.
A partir de cet exemple de réalisation qui a permis de constater dans la mise en oeuvre du procédé conforme à l'invention les avantages du dépôt sur le modèle d'un agent d'adhérence de nombreux avantages dont certains ont déjà été signalés et notamment :
- la suppression de l'adjonction de produits tensio-actifs dans les barbotines et des inconvénients qui en découlaient ;
- l'obtention d'une liaison entre les surfaces du modèle et de la carapace présentant une bonne résistance mécanique ;
- une tolérance plus importante vis à vis des conditions de séchage,
des variantes de réalisation restent possibles.From this exemplary embodiment which made it possible to observe in the implementation of the method according to the invention the advantages of depositing on the model of an adhesion promoter numerous advantages, some of which have already been reported and in particular:
- the elimination of the addition of surface-active products in the slip and of the drawbacks which ensued therefrom;
- obtaining a bond between the surfaces of the model and the shell having good mechanical strength;
- a greater tolerance with regard to drying conditions,
alternative embodiments remain possible.
L'efficacité de l'agent d'adhérence a été testée sur diverses cires et sur un matériau de modèle de type rhodoïd.The effectiveness of the adhesion agent was tested on various waxes and on a rhodoid-type model material.
Les essais décrits ci-dessus ont été réalisés en utilisant des barbotines en suspensions aqueuses comportant un liant à base de silice colloïdale. Mais des applications peuvent également être envisagées avec des suspensions en milieu alcool, notamment en utilisant des barbotines comportant du silicate d'éthyle.The tests described above were carried out using slurries in aqueous suspensions comprising a binder based on colloidal silica. However, applications can also be envisaged with suspensions in an alcohol medium, in particular by using slips comprising ethyl silicate.
Le mode d'application de la solution comportant l'agent d'adhérence qui a été décrit par immersion peut être effectué par aspersion.The mode of application of the solution comprising the adhesion agent which has been described by immersion can be carried out by spraying.
Par ailleurs, en dehors des produits commerciaux signalés, l'agent d'adhérence peut être obtenu à partir d'un produit de type aminosilane.Furthermore, apart from the commercial products reported, the adhesion agent can be obtained from an aminosilane type product.
On notera enfin, comme avantage du procédé selon l'invention offrant de grandes souplesses d'utilisation, qu'il permet, en effectuant un dépôt sélectif de l'agent d'adhérence sur certaines zones choisies d'un modèle, de n'effectuer un dépôt de couche céramique que sur ces parties intéressantes du modèle.Finally, it will be noted, as an advantage of the method according to the invention offering great flexibility of use, that it allows, by effecting a selective deposition of the adhesion agent on certain selected areas of a model, to effect a ceramic layer deposit only on these interesting parts of the model.
En fonction des contraintes de fabrication, le procédé classique utilisant une barbotine épaisse peut être conservé en incorporant l'étape préalable du dépôt de l'agent d'adhérence, conformément à l'invention et en conservant les avantages d'amélioration de l'encollement à l'interface cire/céramique et évitant les décohésions ultérieures, en cas de surséchage notamment.Depending on the manufacturing constraints, the conventional process using a thick slip can be preserved by incorporating the prior step of depositing the adhesion agent, in accordance with the invention and by retaining the advantages of improving the sizing at the wax / ceramic interface and avoiding subsequent decohesions, especially in the case of overdrying.
Claims (5)
(a) - dépôt sur le modèle d'un agent d'adhérence ;
(b) - dépôt d'une couche d'une suspension de céramiques à partir d'une barbotine fluide ;
(c) - séchage ;
(d) - dépôt d'une nouvelle couche de suspension de céramiques à partir de la même barbotine fluide précédemment utilisée à l'étape (b) ;
(e) - dépôt de grains de céramique en stucco ;
<(f) - séchage,
les étapes (d) à (f) étant, de manière connue en sol, répétées autant de fois qu'il est nécessaire pour obtenir les épaisseurs et les caractéristiques du moule recherchées et suivies d'un traitement thermique de cuisson et consolidation du moule par frittage avec élimination du modèle organique,
caractérisé en ce que l'agent d'adhérence déposé à ladite étape (a) du procédé est constitué d'une solution à 3% d'un produit de type aminosilane dans un solvant obtenu par mélange d'éthanol et d'acétate d'éthyle, chacun dans une proportion comprise entre 25% et 75% du solvant.1. Method for manufacturing shell molds for foundries using a model, in particular in wax, of the foundry part to be produced, comprising the following successive steps:
(a) - deposit on the model of a bonding agent;
(b) - deposition of a layer of a ceramic suspension from a fluid slip;
(c) - drying;
(d) - deposition of a new layer of ceramic suspension from the same fluid slip previously used in step (b);
(e) - deposition of ceramic grains in stucco;
<(f) - drying,
steps (d) to (f) being, in known manner in soil, repeated as many times as necessary to obtain the thicknesses and the characteristics of the mold sought after and followed by a heat treatment for baking and consolidation of the mold by sintering with elimination of the organic model,
characterized in that the adhesion agent deposited in said step (a) of the process consists of a 3% solution of an aminosilane type product in a solvent obtained by mixing ethanol and acetate ethyl, each in a proportion of between 25% and 75% of the solvent.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8909760A FR2649917A1 (en) | 1989-07-20 | 1989-07-20 | PROCESS FOR THE MANUFACTURE OF SHELL MOLDS FOR FOUNDRY |
| FR8909760 | 1989-07-20 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0409726A1 true EP0409726A1 (en) | 1991-01-23 |
| EP0409726B1 EP0409726B1 (en) | 1992-12-02 |
Family
ID=9383956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP90402066A Expired - Lifetime EP0409726B1 (en) | 1989-07-20 | 1990-07-18 | Method for fabricating foundry shell moulds |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US5159970A (en) |
| EP (1) | EP0409726B1 (en) |
| DE (1) | DE69000528T2 (en) |
| FR (1) | FR2649917A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2742096C1 (en) * | 2020-07-02 | 2021-02-02 | Владимир Михайлович Волков | Method of making casting molds in investment pattern |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4116609A1 (en) * | 1991-01-19 | 1992-07-23 | Thyssen Industrie | METHOD FOR PRODUCING CERAMIC SHELLS AS CASTING FORM |
| US5266252A (en) * | 1992-09-22 | 1993-11-30 | The United States Of America As Rperesented By The Administrator Of The National Aeronautics And Space Administration | Ceramic slip casting technique |
| HU9203993D0 (en) * | 1992-12-17 | 1993-03-29 | Gal | Method for making wax model for precision casting |
| US6180034B1 (en) * | 1997-09-19 | 2001-01-30 | The United States Of America As Represented By The Administrator Of The National Aeronatics And Space Administration | Process for making ceramic mold |
| ES2218160T3 (en) * | 1999-08-25 | 2004-11-16 | Dentsply International, Inc. | BINDING COMPOSITION FOR COQUILLAS MOLDS AND PROCEDURE. |
| US20060144556A1 (en) * | 2000-03-16 | 2006-07-06 | Wang Ming-Jong P | Shell mold binder composition and method |
| US7631557B2 (en) * | 2007-01-24 | 2009-12-15 | Debeliso Mark | Grip force transducer and grip force assessment system and method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2908952A (en) * | 1957-05-22 | 1959-10-20 | Gen Motors Corp | Method of forming an investment mold |
| FR2255977A1 (en) * | 1973-12-26 | 1975-07-25 | Howmet Corp | |
| EP0251847A1 (en) * | 1986-06-10 | 1988-01-07 | Societe Nationale D'etude Et De Construction De Moteurs D'aviation "Snecma" | Cristobalitic foundry shell mould, composition of the slurry and method of making the mould |
Family Cites Families (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1208255A (en) * | 1900-01-01 | |||
| US2064143A (en) * | 1935-02-23 | 1936-12-15 | Seiberling Latex Products Comp | Rubber glove and process of making same |
| US2703913A (en) * | 1950-02-06 | 1955-03-15 | Bristol Aeroplane Co Ltd | Precision casting |
| US2961751A (en) * | 1958-01-13 | 1960-11-29 | Misco P C Inc | Ceramic metal casting process |
| US3156023A (en) * | 1961-05-16 | 1964-11-10 | Hockin John | Method of investment casting |
| US3396775A (en) * | 1965-11-24 | 1968-08-13 | Dresser Ind | Method of making a shell mold |
| GB1308958A (en) * | 1970-03-20 | 1973-03-07 | Monsanto Chemicals | Production of ceramic moulds |
| DE2019099C3 (en) * | 1970-04-21 | 1975-11-20 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Process for the production of a stable surface protection for semiconductor components |
| JPS528854B2 (en) * | 1972-01-13 | 1977-03-11 | ||
| US3975554A (en) * | 1974-10-15 | 1976-08-17 | Dow Corning Corporation | Process for priming |
| CA1035539A (en) * | 1975-09-26 | 1978-08-01 | Her Majesty In Right Of Canada As Represented By The Minister Of Energy, Mines And Resources | Method of forming foundry moulds |
| JPS6017230B2 (en) * | 1977-07-06 | 1985-05-01 | 三井フロロケミカル株式会社 | Primer for enhancing the peel strength of fluorine-containing resin coatings |
| SU871998A1 (en) * | 1978-08-30 | 1981-10-15 | Предприятие П/Я М-5481 | Solution for treating investment patterns |
| SU865488A1 (en) * | 1979-07-30 | 1981-09-23 | Научно-Исследовательский Институт Специальных Способов Литья | Method of making moulds by the investment pattern method |
| JPS5662869A (en) * | 1979-10-27 | 1981-05-29 | Kanegafuchi Chem Ind Co Ltd | Primer composition |
| JPS5744690A (en) * | 1980-08-29 | 1982-03-13 | Sanyo Chem Ind Ltd | Primer for sealing earthenware pipe |
| FR2510923B1 (en) * | 1981-08-07 | 1986-07-04 | Metalimphy | PROCESS FOR MAKING A MOLD ELEMENT WITH A CERAMIC SHELL AND MOLD ELEMENT OBTAINED |
| SU1101317A1 (en) * | 1982-07-30 | 1984-07-07 | Институт проблем литья АН УССР | Method of manufacturing multilayer shell casting moulds |
| SU1205986A1 (en) * | 1982-07-30 | 1986-01-23 | Отделение ордена Ленина института химической физики АН СССР | Method of producing multilayer shell investment moulds |
| JPS59215241A (en) * | 1983-05-19 | 1984-12-05 | Sumitomo Deyurezu Kk | Resin coated sand for shell mold |
| EP0153432A1 (en) * | 1984-02-29 | 1985-09-04 | Dentsply International, Inc. | Artificial stuccs material,process for making it and use thereof |
| US4832748A (en) * | 1986-10-21 | 1989-05-23 | Toagosei Chemical Industry Co., Ltd. | Coating composition |
| JPH01197568A (en) * | 1988-02-01 | 1989-08-09 | Chisso Corp | Primer |
-
1989
- 1989-07-20 FR FR8909760A patent/FR2649917A1/en active Pending
-
1990
- 1990-07-18 EP EP90402066A patent/EP0409726B1/en not_active Expired - Lifetime
- 1990-07-18 DE DE9090402066T patent/DE69000528T2/en not_active Expired - Fee Related
- 1990-07-20 US US07/554,399 patent/US5159970A/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2908952A (en) * | 1957-05-22 | 1959-10-20 | Gen Motors Corp | Method of forming an investment mold |
| FR2255977A1 (en) * | 1973-12-26 | 1975-07-25 | Howmet Corp | |
| EP0251847A1 (en) * | 1986-06-10 | 1988-01-07 | Societe Nationale D'etude Et De Construction De Moteurs D'aviation "Snecma" | Cristobalitic foundry shell mould, composition of the slurry and method of making the mould |
Non-Patent Citations (2)
| Title |
|---|
| PATENT ABSTRACTS OF JAPAN, vol. 10, no. 273 (M-518)[2329], 17 septembre 1986; & JP-A-61 095 735 (SUMITOMO DEYUREZU K.K.) 14-05-1986 * |
| PATENT ABSTRACTS OF JAPAN, vol. 9, no. 87 (M-372)[1810], 17 avril 1985; & JP-A-59 215 241 (SUMITOMO DUREZ K.K.) 05-12-1984 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2742096C1 (en) * | 2020-07-02 | 2021-02-02 | Владимир Михайлович Волков | Method of making casting molds in investment pattern |
Also Published As
| Publication number | Publication date |
|---|---|
| US5159970A (en) | 1992-11-03 |
| EP0409726B1 (en) | 1992-12-02 |
| DE69000528T2 (en) | 1993-06-03 |
| DE69000528D1 (en) | 1993-01-14 |
| FR2649917A1 (en) | 1991-01-25 |
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