EP0451467B1 - Méthode de frittage utilisant un moule déformable en céramique - Google Patents

Méthode de frittage utilisant un moule déformable en céramique Download PDF

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Publication number
EP0451467B1
EP0451467B1 EP91102428A EP91102428A EP0451467B1 EP 0451467 B1 EP0451467 B1 EP 0451467B1 EP 91102428 A EP91102428 A EP 91102428A EP 91102428 A EP91102428 A EP 91102428A EP 0451467 B1 EP0451467 B1 EP 0451467B1
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EP
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Prior art keywords
mould
component
ceramic
sintering
powder
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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EP91102428A
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German (de)
English (en)
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EP0451467A1 (fr
Inventor
Reinhard Fried
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ABB Asea Brown Boveri Ltd
ABB AB
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ABB Asea Brown Boveri Ltd
Asea Brown Boveri AB
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B22F3/1216—Container composition
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/12—Both compacting and sintering
    • B22F3/1208—Containers or coating used therefor
    • B22F3/1258—Container manufacturing
    • B22F3/1283—Container formed as an undeformable model eliminated after consolidation

Definitions

  • the invention relates to the further development, perfection and simplification of powder metallurgical manufacturing methods for the production of workpieces with comparatively complicated shapes, where the problems of shrinkage during sintering play an important role.
  • the main area of application is in the area of components for turbine construction.
  • the invention relates to a method for shaping any component from a metallic and / or ceramic material, starting from a powder or a powder mixture, the powder being poured loosely into a mold and then subjected to a sintering process.
  • the invention has for its object to provide a method with which, starting from metal or ceramic powders, a comparatively complicated shaped component of any cross-section and unlimited wall thickness can be manufactured.
  • the process is intended to provide a reproducible finished product that no longer has to be processed, or at most only slightly. When processing powder bubbles and unwanted harmful residues should be avoided.
  • the process is intended to ensure the greatest possible freedom of movement and universality.
  • FIG. 1 shows a flow diagram (block diagram) of the method using an elastic / plastically yielding form.
  • the diagram needs no further explanation.
  • the shape is made of a resilient material and is designed to accommodate the movements of the sintered body to be produced follows without tearing or breaking.
  • FIG. 2 shows a flow diagram (block diagram) of the method using a flexible form with predetermined breaking points.
  • the shape here consists of a material that breaks at certain points as soon as the body to be sintered has sufficient inherent strength. The shape broken or torn in this way then no longer offers any appreciable resistance to the solidifying sintered body, so that it can expand or contract in all directions without being severely prevented.
  • this category of form includes all variants in which the form undergoes more or less irreversible changes in the course of the sintering process of the workpiece: the form tears, breaks, disintegrates, is at least locally crushed, etc.
  • the shape need not necessarily have predisposed predetermined breaking points as notches, grooves, etc. The "predetermined breaking point" can also occur arbitrarily where the strength of the material is exceeded. After the sintering process, the destroyed form is not ready for use again.
  • Fig. 3 relates to a schematic elevation / section of a yielding split mold with powder filling for the purpose of demonstrating the principle of conformity when shrinking: state before shrinking.
  • 1 represents the powder filling (powder filling) for the component.
  • 2 is a yielding split mold made of ceramic material in the state before the component shrinks (heat treatment, sintering process).
  • 4 shows a schematic elevation / section of a yielding split mold with a sintered body for the purpose of demonstrating the principle of conformity during shrinking: state during shrinking (even after the shrinking process has ended during the sintering process).
  • 3 is the solidifying sintered body (component, workpiece) formed from the powder in the meantime.
  • 4 shows the yielding split form made of ceramic material during and after the shrinking of the component.
  • the shrinkage is only shown in the direction of the main longitudinal axis, while that in the transverse direction has not been taken into account.
  • the direction of movement during the shrinking process of the component is indicated by opposite vertical arrows. At the same time, these arrows represent the longitudinal compression forces acting on the ceramic mold. The mold is thus compressed in the present case.
  • 5 is the original contour (dashed line) of the yielding shape before the component shrinks (see FIG. 3).
  • FIG. 5 shows a schematic elevation / section of a yielding split mold and a finished sintered body for the purpose of demonstrating the principle of conformity during shrinkage: state after removal of the filled mold.
  • 3 is the sintered body
  • 6 the divided form made of ceramic material after its removal. After releasing the tension, the elastic shape (in this case two halves) almost returns to its original shape.
  • the arrows show the direction of movement of the molded parts when they are removed from the workpiece.
  • FIG. 6 shows a schematic elevation / section of a detail from a yielding form for the purpose of demonstrating the principle of the predetermined breaking point when shrinking.
  • 7 is any section of a compliant shape made of ceramic material. This stylized example can be easily applied to the case of the side boundary transferred to a turbine blade with cantilevered head and foot sections.
  • 8 represents an expansion piece (bulge, bulge) of the yielding shape. This part serves to deflect the forces (pressure forces p) and to generate a bending moment (M b ) at the predetermined breaking point 9, which is subjected to bending when the component shrinks. In addition, such a bulge provides the space for the movement of the mold caused by the shrinkage of the component.
  • FIG. 7 relates to a schematic elevation / section of a yielding shape with predetermined breaking points and a powder filling: state before shrinking.
  • 1 is the powder filling for the component
  • 10 is the yielding undivided form made of ceramic material with predetermined breaking points before the component shrinks.
  • 8 is an expansion piece in the form of a parabolic bulge with predetermined breaking point 9 in the form of a notch (groove) 11.
  • the space enveloped by the expansion piece 8 is closed off from the workpiece side by an elastic-plastic ceramic seal 12 in the manner of a fleece or felt or flexible fiber product.
  • FIG. 8 shows a schematic elevation / section of a yielding shape with broken predetermined breaking points and a sintered body: state during shrinking during sintering.
  • 3 shows the sintered body, shrunk in the longitudinal direction compared to the powder filling 1 (FIG. 7).
  • 9 is a predetermined breaking point (shape already broken).
  • 13 is a part of the yielding undivided shape made of ceramic material during and after the shrinking of the component.
  • 12 is the elastic-plastic ceramic seal, which has been squeezed here in part by compressing it into the space available transversely.
  • 14 shows a crack in a part of the mold made of ceramic material during and after the component has shrunk. In the present case, the crack 14 gapes at this point due to high bending moments. If the shrinkage is severe, they break cantilevered expansion pieces (8 in Fig. 7) completely or are even crushed.
  • FIG. 9 shows a schematic elevation / section of a yielding shape with broken predetermined breaking points and a finished sintered body: state after the fragments of the cracked shape have been removed.
  • 3 is the sintered body, 12 the elastic-plastic ceramic seal and 15 each a fragment of the yielding shape made of ceramic material after removal.
  • 16 is an irregular fracture surface at the predetermined breaking point of the mold.
  • the crack 14 in a fragment is drawn in closed after the bending moment ceases to exist. In contrast, the lowest fragments 15 are completely broken through. There are all variants of the destroyed form.
  • the arrows indicate the direction of movement of the fragments 15 when they are removed from the component to be manufactured.
  • FIG. 10 shows a schematic elevation / section of a thin-walled, yielding shape with numerous notches as predetermined breaking points and a powder filling: state before shrinking.
  • the reference numerals correspond to those of FIG. 7.
  • the wall thickness of the mold 10 is greatly reduced compared to FIG. 5.
  • the notches 11 of the predetermined breaking points have a parabolic profile and are predominantly located at the thickened corners of the mold 10. As a result, bending moments are generated during the shrinkage, which cause the shell-like mold 10 to break open.
  • 11 relates to a schematic section of a section of a form consisting of several ceramic layers and a sintered body.
  • the detail shows a sintered body 3 at the location of a rib with a rectangular cross section.
  • the mold in the present case represents a shell-like body made of different layers.
  • 17 is a smooth inner skin of the mold made of ceramic material. This is usually done with a fine-grained mass, Paste (slip, etc.) used.
  • 18 is the essentially shape-determining middle-fine-grained inner layer (shell) of the form made of ceramic material. Their relatively dense grains are drawn as more or less globular particles.
  • 19 is the coarse-grained middle layer (shell) of the form. 20 represents the coarse-pored, framework-like outer layer of the mold.
  • FIG. 12 shows a schematic section of a detail from a mold consisting of a highly porous foam ceramic layer and a mechanically stronger glass ceramic layer and a sintered body: state before cracking during sintering.
  • 21 is an inner layer (shell) of the form made of highly porous foam ceramic. The latter has rough, continuous pores 22.
  • FIG. 13 shows a schematic section of a section from a mold consisting of a highly porous foam ceramic layer and a glass ceramic layer and a sintered body: state after tearing and crumbling.
  • the reference numerals 3, 17, 21, 22, 23 are exactly the same as in Fig. 12.
  • 24 is a crack in the foam ceramic of the mold, which runs approximately perpendicular to the workpiece surface (sintered body 3). The cracks 24 partially follow the pores 22 in this layer 21.
  • 25 is the corresponding crack in the glass ceramic of the mold. It is the case where tensile and bending stresses occur in layers 21 and 23.
  • FIG. 14 shows a schematic elevation / section of a yielding mold consisting of a ductile ceramic film with powder filling: state before shrinking.
  • 1 is the powder filling for the production of the component.
  • 26 is a thin ductile ceramic sheet used in the green or semi-dry or partially heat-treated condition. It is placed in a preform and heat treated for solidification or otherwise subjected to a hardening process. The powder is filled through a filling opening 27. 28 is a seal (adhesive joint) in the ceramic film.
  • 15 relates to a schematic elevation / section of a yielding mold consisting of a sintered ceramic film with a sintered body: state after shrinking by sintering together.
  • 3 is the sintered body, 20 the shell made of the sintered ceramic film.
  • the arrows indicate the direction of movement during the shrinking process of the component. Since the shell 29 also shrinks at the same time, only the differential forces come into effect at the interfaces between the shell 29 and the sintered body 3. These can be positive or negative, depending on whether the shrinkage of the component or that of the shape predominates. In the first case, compressive forces arise in the mold (shell 29), in the second case tensile forces. It is advantageous to coordinate the shrinkage mass with one another by choosing the materials involved in each of FIGS. 3 and 29. A special case occurs when both shrinkage masses are the same. Then no forces are transferred.
  • the yielding (i.e., elastic-plastically compliant or tearing) forms are produced according to the well-known conventional process of foundry and plastic molding technology and related technologies. Accordingly, the mold is usually produced using a model, the dimensions of which take into account the subsequent shrinkage when the powder is sintered to produce the component.
  • the method of melting wax, low-temperature metals and alloys, washing out salt or urea, burning out synthetic foam, etc. is practiced.
  • the ceramic material required for the mold is applied to the model using the immersion, paste, casting and spraying process.
  • Multi-part molds are usually made using models, dies, preforms, etc.
  • Indestructible, elastic-plastic yielding forms are usually designed as thin-walled, highly porous shells, usually made up of several layers.
  • Destructible shapes either have predetermined, defined predetermined breaking points or consist of thin shells that form network-like polygonal cracks under the forces that occur or disintegrate into mosaic-like fragments. These forces can also be triggered by process control (temperature, chemical reactions, structural changes).
  • the powder was produced by gas jet atomization and had a maximum particle size of 50 »m.
  • the powder was filled dry, without any binder, into a ceramic form which gave about 10% more linear expansion, and cold pre-compacted by vibration.
  • the procedure for producing the following mold was as follows: First of all, two preforms (matrices) for a two-part ceramic mold were produced, which depicted the component to be manufactured as a hollow mold, linearly enlarged by the shrinkage 10%.
  • the filled, cold pre-compressed steel powder was sintered under vacuum (residual pressure 10 ⁇ 7 bar).
  • the vacuum furnace and workpiece were first heated to 1000 ° C at a rate of 20 ° C / min, then to 1200 ° C at a rate of 5 ° C / min.
  • the steel powder had the opportunity to sinter to such an extent that the workpiece already had sufficient inherent strength without having undergone any significant shrinkage.
  • the workpiece to be sintered was further heated to a sintering temperature of 1360 ° C. and sintered for 6 hours.
  • the yielding ceramic mold which consisted of simultaneously sintered casting compound, reached the temperature such that it offered practically no resistance to the shrinkage of the steel component to be produced, but essentially retained its desired shape. Then the whole thing was cooled in the oven to approx. 250 ° C, whereby the shell-like ceramic shape cracked due to different thermal expansion coefficients and some shell parts were already flaking off. After removal from the oven, the component with the still adhering shell parts of the mold was quenched in cold water, the latter flaking off completely. The component was cleaned by blasting with glass beads, which resulted in a clean, smooth surface.
  • Example I As a component, a blade corresponding to Example I was made from the Cr steel X20CrMoV 12 1 with the same dimensions.
  • the divided metallic preforms (matrices) as used in Example I were used as tools.
  • the residual moisture (H2O content) was approximately 2.5 to 3% by weight. 0.5% by volume of a silicate-based binder with the trade name "Silester X15" from Monsanto, Brussels, Belgium, was added to the mass with particles of up to 630 »m. It was filled into the die with vibration and pressing with a stamp. The green compact produced in this way had sufficient inherent strength to be handled for drying.
  • the binder fraction was cured on the way of a chemical reaction by treatment in an atmosphere containing NH 3 (ammonia curing) for 5 min. The ceramic mold was then air-dried for 30 minutes. The drying time depends on the dimensions the form approx. 10 to 60 min. This time was used to fill the resilient ceramic mold made of shells with the powder made of Cr steel.
  • the ceramic mold there was no need to fire the ceramic mold separately.
  • the filled mold was moved into a vacuum oven, heated and sintered simultaneously with the powder of the component to be manufactured. Due to the low proportion of binder in the mold, the pollution of the furnace atmosphere is negligible. During this heat treatment there was considerable shrinkage in the mold, so that the latter guaranteed sufficient support of the steel particles of the workpiece at all times without, however, hindering them from shrinking themselves.
  • the time / temperature program was carried out in such a way that the shrinkage of the workpiece and the shape took place at approximately the same speed and the same degree. In the present case, the whole was first heated to 1100 ° C. at a speed of approx.
  • the powder used was generated by gas jet atomization and had a maximum particle size of 30 »m.
  • a compliant ceramic mold based on Si02 was made of two shells.
  • the principle of segregation of multiphase batches of special silicate glasses was used (see spinodal segregation).
  • B203 20% by weight
  • Na20 20% by weight
  • 3 mm thick shells were produced from the borosilicate glass using dies as tools, cemented together and the shape formed in this way was subjected to heat treatment.
  • the borosilicate separated into an almost pure, insoluble Si02 phase and a local sodium borate phase. The latter was dissolved out with 3N sulfuric acid, so that a microporous Si02 skeleton which retained the shape remained.
  • the Cr / Ni steel powder was filled into this mold and the whole was heated to 1000 ° C.
  • the steel powder sintered successively from 900 ° C in such a way that it already assumed sufficient inherent strength.
  • the spongy structure of the mold shrank linearly by 15 to 20%.
  • the shape broke partially, while other parts of it softened. Shortly before this state was reached, a pressure was exerted from the mold onto the workpiece perpendicular to the surface, which at least locally compressed the latter. This effect is desirable because it leads to a denser component.
  • the complete sintering aimed at a component that was as dense as possible was dispensed with and the entire heat treatment was stopped prematurely (presintering).
  • the whole, the component and the shape as a glass-encased workpiece was cooled and compressed into the finished part in a corresponding system by hot isostatic pressing.
  • the glass and time / temperature program had previously been coordinated in such a way that there was no need to fear recrystallization or breakage due to the stresses occurring at the Si02 conversion.
  • a blade corresponding to Example II was made of AISI 316 Cr / Ni steel. The dimensions were exactly the same as in Example III. The same matrices were also used.
  • a paste-like mass of a foaming ceramic material based on sodium metasilicate was applied by spraying / spraying onto the positive molding of the respective die, dried, cured and detached from the die.
  • the two thin shells produced in this way had a wall thickness of 0.5 mm. They were glued together to give the ceramic form and filled with Cr / Ni steel powder.
  • the whole workpiece, consisting of mold and powder filling was placed in a box with a sand bed, surrounded on all sides with sand and heated to a temperature of 600 ° C. In the course of heating, the ceramic mass of the mold began to foam, creating a highly porous, foam-like structure which displaced a corresponding volume of sand in the sand bed.
  • the non-foamed skin-like inner wall of the shape thus formed was supported against the inside on the steel powder.
  • the brittle foam ceramic was compressed (pressed in) in the zones near the surface by the shrinking process, but the partially broken framework of the component did not offer any appreciable resistance.
  • a component with a comparatively smooth surface could be achieved.
  • An approximate final shape of the component having multi-part metallic matrix was coated on the outside by flame spraying with an approximately 0.8 mm thick Al2O3 layer as an outer shell.
  • Prismatic rectangular cores for the channels with grooves for the ribs were then produced.
  • the material mullite (3Al2O3 ⁇ 2SiO2) was used in coarse-grained powder form with a particle diameter of 200 to 500 »m, to which a few percent by weight quartz (SiO2) was added as a binder.
  • the yielding ceramic form composed of several Al2O3 shell parts and mullite cores was then filled with vibration with SiC powder of 30 to 80 »m particle size and the whole was subjected to a time-programmed heat treatment.
  • the mixture was heated to a temperature of 300 ° C. at a rate of 100 ° C./h and held at this value for about 1/2 hour.
  • the further heating to 1000 ° C was carried out at 200 ° C / h and that to 1100 ° C at a reduced speed of 20 ° C / h to the expected conversions (phases, modifications of SiO2 etc.) and the resulting volume changes leave time for the substances involved.
  • the mixture was then heated to 1500 ° C. at 200 ° C./h and this temperature was maintained for 2 hours.
  • the mullite already began to soften somewhat, so that it did not hinder the shrinkage of the silicon carbide component to be produced in the sintering process that now began. This was now at a temperature of 1600 ° C for 8 hours carried out. The cores shrank with it and the outer shell of the form (Al2O3) remained. Upon completion of the sintering process, cooling (quenching) took place relatively quickly, forcing the outer shell of the mold to come off while the cores were crumbling. With this example it could be shown that even comparatively complex components made of ceramic materials can be economically manufactured using the present process.
  • the invention is not restricted to the exemplary embodiments.
  • the method for shaping any component made of a metallic and / or ceramic material starting from a powder or a powder mixture, the powder being poured loosely into a mold and then subjected to a sintering process is carried out by using a flexible ceramic body as the mold , which yields elastically and / or plastically under the stresses that occur due to expansion or shrinkage, causing tensile and / or compressive forces due to expansion or shrinkage, and / or tears at targeted predetermined breaking points, however, its strength and dimensional stability in the entire temperature range and above the entire process sequence is sufficiently high to ensure a high dimensional accuracy of the component to be manufactured as a sintered body.
  • One or more thin, flexible ceramic shells made of Al2O3, SiO2 or MgO of high porosity or a body made of a special glass are used as the mold, which, when the sintering temperature of the powder mixture intended for the component is reached, tears in a net-like manner without completely breaking or disintegrating.
  • a ceramic body is preferably used as the mold, which has predetermined breaking points in the form of notches at the locations of the highest tensile stresses in the course of the sintering process, and also a ceramic shell that tears when the component is sintered and breaks down into arbitrary mosaic-like fragments.
  • a thin, flexible, elastic-plastic ceramic film in the green or only partially heat-treated state is used as the mold, which only in the course of the heating and sintering process, together with the powder used to produce the component, achieve its final strength through chemical processes and finished sintering receives.
  • a green ceramic mass is advantageously used as the mold, which assumes its final shape and strength only during the drying and sintering process at the same time as the component is being sintered, with the associated shrinkage process only the positive or negative due to the different shrinkage of the shape and component Differential forces must be absorbed.
  • Particularly favorable conditions are present if a material is used for the ceramic mass whose shrinkage due to the heating and sintering of the shape and the component is greater than the shrinkage of the powder used for the component, such that the component is during pressure is exerted during the sintering process while the wall of the mold is under tension.
  • the powder or the powder mixture is preferably precompressed in the yielding form by centrifugal force centrifugation before heating to the sintering temperature or during the first phase of heating in the lower temperature range.

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  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Powder Metallurgy (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Multi-Conductor Connections (AREA)
  • Moulds, Cores, Or Mandrels (AREA)

Claims (9)

  1. Procédé de fabrication d'un composant de construction en matériau métallique et/ou céramique, qui présente les opérations de base suivantes:
    (a) la préparation d'une poudre ou d'un mélange de poudres correspondant en tant que matériau de départ,
    (b) le remplissage de manière non tassée du matériau de départ dans un moule, qui est conçu en tant que corps céramique souple qui cède élastiquement et/ou plastiquement sous l'effet des forces de traction et/ou de compression qui apparaissent à la suite d'une dilatation ou d'un retrait lors d'élévations de température et lors de procédures de frittage et qui se fissure, le cas échéant, en des points de rupture prévus à cet effet,
    (c) l'introduction du moule rempli du matériau de départ dans un four,
    (d) le chauffage du moule rempli de matériau de départ libre de toute pression externe à une température à laquelle le frittage du matériau de départ a lieu, le programme temps/température étant conduit de sorte que la contraction du matériau de départ et la contraction du moule se produisent à une vitesse et dans une mesure approximativement égales,
    (e) la fissuration du moule après atteinte d'une résistance et d'une stabilité de forme suffisamment élevées du matériau de départ au moins préfritté pour garantir un précision de forme élevée du composant de construction destiné à être fabriqué en tant que corps de frittage, et
    (f) l'enlèvement du moule fissuré du composant de construction fini.
  2. Procédé selon la revendication 1, caractérisé en ce que l'on utilise en tant que moule une ou plusieurs coupes céramiques souples minces en Al₂O₃, SiO₂ ou MgO de porosité élevée.
  3. Procédé selon la revendication 1, caractérisé en ce que l'on utilise en tant que moule un corps en verre spécial, qui se fissure en formation de peau de crocodile, une fois atteinte la température de frittage du mélange de poudres spécifié pour le composant de construction, sans complètement éclater ou se désagréger.
  4. Procédé selon la revendication 1, caractérisé en ce que l'on utilise en tant que moule un corps céramique, qui présente des points de rupture intentionnels en forme d'entailles aux endroits où apparaissent, au cours du processus de frittage, les tensions de traction les plus élevées.
  5. Procédé selon la revendication 1, caractérisé en ce que l'on utilise en tant que moule une coupe en céramique qui se fissure lors du frittage du composant de construction et qui se désagrège en fragments arbitraires en forme de mosaïque.
  6. Procédé selon la revendication 1, caractérisé en ce que l'on utilise en tant que moule une feuille céramique mince, flexible, élastique-plastique à l'état vert ou à l'état ayant subi seulement un traitement thermique partiel, qui n'atteint sa résistance ultime à la suite de processus chimiques et d'un frittage final qu'au cours du processus de chauffage et de frittage, conjointement à la poudre utilisée pour la fabrication du composant de construction.
  7. Procédé selon la revendication 2, caractérisé en ce que l'on utilise en tant que moule une masse céramique vertes qui ne prend sa forme et résistances ultimes que lors du processus de séchage et de frittage en même temps que lors du frittage du composant de construction, seules les forces différentielles positives ou négatives conditionnées par la contraction différente du moule et du composant de construction devant être absorbées lors du processus de retrait associe.
  8. Procédé selon la revendication 7, caractérisé en ce que l'on utilise pour la masse céramique un matériau dont la contraction lors du retrait conditionné par le chauffage et le frittage du moule et du composant de construction est supérieure à la contraction de la poudre utilisée pour la pièce, de sorte qu'une pression est exercée sur le composant de construction pendant le processus de frittage, alors que la paroi du moule est soumise à un effort de traction.
  9. Procédé selon la revendication 1, caractérisé en ce que l'on procède à la prédensification par centrifugation, dans le moule souple, de la poudre ou du mélange de poudres avant le chauffage à la température de frittage ou pendant la première phase du chauffage dans le domaine de températures inférieur.
EP91102428A 1990-03-14 1991-02-20 Méthode de frittage utilisant un moule déformable en céramique Expired - Lifetime EP0451467B1 (fr)

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CH81790 1990-03-14
CH817/90 1990-03-14

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EP0451467A1 EP0451467A1 (fr) 1991-10-16
EP0451467B1 true EP0451467B1 (fr) 1995-02-08

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US (1) US5077002A (fr)
EP (1) EP0451467B1 (fr)
JP (1) JPH04224606A (fr)
AT (1) ATE118182T1 (fr)
DE (1) DE59104523D1 (fr)

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US5468193A (en) * 1990-10-25 1995-11-21 Sumitomo Heavy Industries, Ltd. Inscribed planetary gear device having powder injection molded external gear
DE4322084A1 (de) * 1993-07-02 1995-01-12 Abb Research Ltd Verfahren zur Herstellung eines Setters
DE59508447D1 (de) * 1994-09-15 2000-07-13 Basf Ag Verfahren zur Herstellung metallischer Formteile durch Pulverspritzguss
US6676895B2 (en) 2000-06-05 2004-01-13 Michael L. Kuhns Method of manufacturing an object, such as a form tool for forming threaded fasteners
US6537487B1 (en) 2000-06-05 2003-03-25 Michael L. Kuhns Method of manufacturing form tools for forming threaded fasteners
US20050227772A1 (en) * 2004-04-13 2005-10-13 Edward Kletecka Powdered metal multi-lobular tooling and method of fabrication
US8601907B2 (en) 2004-09-24 2013-12-10 Kai U.S.A., Ltd. Knife blade manufacturing process
US20070274854A1 (en) * 2006-05-23 2007-11-29 General Electric Company Method of making metallic composite foam components
US20070295785A1 (en) * 2006-05-31 2007-12-27 General Electric Company Microwave brazing using mim preforms
US7845549B2 (en) * 2006-05-31 2010-12-07 General Electric Company MIM braze preforms
GB2517939B (en) * 2013-09-05 2016-08-10 Rolls Royce Plc A method and apparatus for separating a canister and component

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1788101A (en) * 1928-07-19 1931-01-06 Major E Gates Mold and method of manufacturing the same
CA855149A (en) * 1968-02-28 1970-11-03 J. Havel Charles Hot isostatic pressing using a vitreous container
US3939241A (en) * 1974-10-04 1976-02-17 Crucible Inc. Method for powder metallurgy compacting
US4164527A (en) * 1974-11-01 1979-08-14 Bakul Valentin N Method of making superhard articles
US4000235A (en) * 1975-05-13 1976-12-28 National Forge Company Method for molding particulate material into rods
GB1557744A (en) * 1976-06-01 1979-12-12 Special Metals Corp Process and apparatus for producing aticles of complex shape
USRE31355E (en) * 1976-06-03 1983-08-23 Kelsey-Hayes Company Method for hot consolidating powder
DE2737266C2 (de) * 1977-08-18 1987-08-20 MTU Motoren- und Turbinen-Union München GmbH, 8000 München Verfahren zur Kapselung eines Formkörpers aus Siliziumkeramik für das heißisostatische Pressen
DE2934465C2 (de) * 1978-09-06 1982-06-16 ASEA AB, 72183 Västerås Verfahren zum gleichmäßig dichten Füllen einer Hülle mit Pulver und Schleudervorrichtung zur Durchführung des Verfahrens
GB2088414B (en) * 1980-11-24 1985-01-09 Nippon Dia Cleviteco Ltd Sintering stainless steel powder
DE3045838C2 (de) * 1980-12-05 1983-01-05 Fried. Krupp Gmbh, 4300 Essen Verfahren zur Herstellung metallischen Halbzeuges
KR890003502B1 (ko) * 1985-02-08 1989-09-23 가부시기가이샤 히다찌세이사꾸쇼 슬립캐스팅 성형법 및 성형용 주형
JPS61273298A (ja) * 1985-05-28 1986-12-03 Nippon Kokan Kk <Nkk> 粉体の成形方法
US4673549A (en) * 1986-03-06 1987-06-16 Gunes Ecer Method for preparing fully dense, near-net-shaped objects by powder metallurgy
US4724123A (en) * 1987-02-09 1988-02-09 The Dow Chemical Company Plastic foam container for the densification of powder material
US4722825A (en) * 1987-07-01 1988-02-02 The United States Of America As Represented By The Secretary Of The Navy Method of fabricating a metal/ceramic composite structure
DE3805193A1 (de) * 1988-02-19 1989-08-31 Nmi Naturwissenschaftl U Mediz Verfahren zur herstellung von hochfesten keramik-fasern und -formkoerpern und ihre verwendung
US4943320A (en) * 1988-12-15 1990-07-24 The Regents Of The University Of California Vapor phase redistribution in multi-component systems

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US5077002A (en) 1991-12-31
DE59104523D1 (de) 1995-03-23
EP0451467A1 (fr) 1991-10-16
JPH04224606A (ja) 1992-08-13
ATE118182T1 (de) 1995-02-15

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