EP0936277A1 - Process for producing an iron-aluminium intermetallic alloy and iron-aluminium intermetallic alloy - Google Patents

Process for producing an iron-aluminium intermetallic alloy and iron-aluminium intermetallic alloy Download PDF

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Publication number
EP0936277A1
EP0936277A1 EP99400282A EP99400282A EP0936277A1 EP 0936277 A1 EP0936277 A1 EP 0936277A1 EP 99400282 A EP99400282 A EP 99400282A EP 99400282 A EP99400282 A EP 99400282A EP 0936277 A1 EP0936277 A1 EP 0936277A1
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Prior art keywords
iron
powder
aluminum
alloy
weight
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EP99400282A
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German (de)
French (fr)
Inventor
Régis Baccino
Frédéric Moret
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Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C33/00—Making ferrous alloys
    • C22C33/02—Making ferrous alloys by powder metallurgy
    • C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C1/00—Making non-ferrous alloys
    • C22C1/04—Making non-ferrous alloys by powder metallurgy
    • C22C1/047—Making non-ferrous alloys by powder metallurgy comprising intermetallic compounds
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C30/00—Alloys containing less than 50% by weight of each constituent
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
    • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
    • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
    • C22C32/0026—Matrix based on Ni, Co, Cr or alloys thereof
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10—Processes characterised by the sequence of their steps
    • 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
    • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy

Definitions

  • the invention relates to a method of manufacture of an iron-aluminum intermetallic alloy, to an iron-aluminum intermetallic alloy which can be obtained by said process, and to an element constituted of such an alloy.
  • Iron-aluminum intermetallic alloys present, compared to other alloys structural, particular properties which are a low density and specific resistance, i.e. a property related to the density of the material, high compared to steels and superalloys. They for example have a high specific rigidity compared to light alloys, steels and nickel alloys, high ductility compared to that of other intermetallics such as TiAl and NiAl, high mechanical resistance up to 700 ° C by compared to aluminum alloys and composites organic matrix, resistance to dry corrosion high compared to most steels and stainless superalloys, and low cost of basic materials.
  • Specific stiffness is a property particularly interesting of these materials. She is in fact 10 to 20% higher than that of structural alloys currently used such as light alloys, steels and superalloys, for the manufacture of parts that must work in vibratory regimes close to resonance limit, or even beyond, such as certain power trees of turbine or certain injection nozzles or pipes of fluid.
  • an iron-aluminum intermetallic alloy In a composition range between 25 to 50% aluminum, an iron-aluminum intermetallic alloy has an ordered crystal phase of centered cubic structures of type B2. This phase ordered, also called first phase, has a excellent resistance in an oxidizing environment, sulfur or fuel, up to 1000 ° C, and good resistance to erosion. But it does, however, great fragility at room temperature and yield strength and creep resistance, little high at high temperature.
  • Iron-aluminum intermetallic alloys are currently manufactured by extrusion processes, from powder mixtures essentially comprising iron and aluminum.
  • the crystalline phase ordinate of this alloy supports the addition of various additional elements which reinforce the properties alloy mechanics.
  • additional elements can be for example nickel, cobalt, titanium, magnesium, zirconium, boron, chromium, cerium or a mixture of these elements, etc ... in varying proportions and combinations.
  • the object of the invention is precisely to provide a process for manufacturing an intermetallic alloy iron-aluminum with a manufacturing cost of the alloy clearly inferior to that entrained by a extrusion process.
  • the method of the invention used to manufacture an alloy having a high mechanical strength and sufficient ductility for many applications.
  • the powder can comprise in in addition to an element chosen from nickel, cobalt, titanium, magnesium, zirconium, boron, chromium, cerium, or a mixture of these.
  • the powder can comprise by example of 20 to 50% by weight of aluminum, and can further comprise from 0.05 to 0.5% by weight of zirconium, from 0.001 to 0.02% by weight of boron, the rest being inevitable iron and impurities.
  • the powder can comprise about 21 to 28% by weight of aluminum, and can further include about 0.08 to about 0.14% in weight of zirconium, about 0.012 to about 0.018% by weight of boron, the rest being iron and impurities inevitable.
  • the particle size of the powder can be in the range of 10 to 500 ⁇ m, preferably in a range from 10 to 50 ⁇ m.
  • the method can also comprise a step of dispersing in the powder an oxide chosen from Y 2 O 3 , Al 2 O 3 , Fe 2 O 3 , or a mixture of these oxides, in the form of a nanometric powder.
  • the method can also comprise a step of dispersing in the powder from about 0.5 to about 1.5% by weight of Y 2 O 3 in the form of a nanometric powder, preferably about 1% by weight of Y 2 O 3 .
  • the powder can be prepared by dry grinding said mixture under a neutral gas.
  • This dry grinding can be carried out for example in a ball mill.
  • the powder is then degassed for example by means of a vacuum pump.
  • the hot compression of the degassed powder can be made at a temperature ranging from about 900 to about 1300 ° C, preferably a temperature ranging from approximately 1000 to approximately 1200 ° C.
  • the hot compression of the degassed powder can be made at a pressure ranging from about 50 to about 400 MPa, preferably at a pressure of about 100 MPa.
  • the compression of the powder can be performed at variable pressure or pressure isostatic.
  • the compression for a period ranging from about 0.5 to about 4 hours, preferably for a period about 2 hours.
  • the invention also relates to an alloy iron-aluminum intermetallic obtainable by the method of the invention, said alloy comprising iron, aluminum, zirconium, boron, and yttrium oxide, and having an elongation about 1.5% and an elastic limit of about 960 MPa.
  • the invention also relates to an alloy iron-aluminum intermetallic obtainable by the method of the invention, said alloy comprising iron, aluminum, zirconium, boron, and yttrium oxide and having an elongation from about 0.2 to about 0.8% and an elastic limit about 1240 MPa.
  • the invention therefore consists in particular in densifying a powder with a particle size determined from a mixture comprising iron and aluminum, by means hot pressing.
  • the dense alloy obtained by this process has properties quite surprising for many applications.
  • This alloy in particular has resistance mechanical can reach or exceed 1000 MPa and a ductility which can exceed 1%.
  • the method of the invention does not have the aforementioned drawbacks of the extrusion processes of prior art.
  • the present invention further makes it possible to manufacture elements of iron-aluminum intermetallic alloy large dimensions. Indeed, the compression of the degassed powder can be made in a container or mold can go for example up to 1 meter diameter and 2 meters in height, without these limits are absolute, to obtain an alloy element iron-aluminum intermetallic having substantially the same dimensions as the container.
  • the container or mold may have a complex shape for making alloy elements iron-aluminum intermetallic complex shape without necessarily have to resort to machining.
  • the method of the invention also makes it possible to manufacture elements from an iron-aluminum intermetallic alloy near the odds or the odds, that is to say that the parts thus manufactured do not require, or little, subsequent machining.
  • a powder of determined particle size is prepared for from a mixture comprising 24% by weight aluminum, 0.11% zirconium, 0.0026% by weight of boron, the balance being iron and impurities inevitable. This mixture is melted to be cast in the form of ingots.
  • This pre-alloyed powder is then ground dry under argon in a ball mill, adding at the start of the milling 1% by weight of Y 2 O 3 .
  • a powder with a particle size between 50 and 300 is obtained.
  • the grinding operation introduces a quantity about 0.03% by weight of oxygen and about 0.01% by weight of carbon in the alloy. Carbon comes wear of the balls in the ball mill during grinding.
  • the ground powder is put in a container and densified by hot isostatic compression at a temperature of 1100 ° C under a pressure of 100 MPa during 2 hours.
  • the mechanical properties of the alloy obtained have been determined under the least conditions favorable to the ductility of such an alloy, that is to say on an unpolished machined part, in air dehydrated and at a low traction speed.
  • this alloy has an elongation of 1.5% and a limit elastic of 960 MPa at room temperature.
  • the crushed powder is put in a container and densified by hot isostatic compression at a temperature of 1000 ° C and under an isostatic pressure of 100 MPa during 2 hours.
  • a piece of iron-aluminum intermetallic alloy near the odds or odds is obtained.
  • This alloy has an elongation of 0.2 to 0.8% and an elastic limit of 1240 MPa.

Abstract

An intermetallic iron-aluminum alloy is produced by hot pressing a degassed powder mixture of iron, aluminum and optionally other components. Independent claims are also included for the following: (i) an intermetallic iron-aluminum alloy containing zirconium, boron and yttrium oxide and having an elongation of 1.5% and an elastic limit of 960 MPa, the alloy being produced as described above; (ii) an intermetallic iron-aluminum alloy containing zirconium, boron and yttrium oxide and having an elongation of 0.2-0.8% and an elastic limit of 1240 MPa, the alloy being produced as described above; and (iii) an intermetallic iron-aluminum alloy element produced as described above.

Description

Domaine technique de l'inventionTechnical field of the invention

L'invention se rapporte à un procédé de fabrication d'un alliage intermétallique fer-aluminium, à un alliage intermétallique fer-aluminium pouvant être obtenu par ledit procédé, et à un élément constitué d'un tel alliage.The invention relates to a method of manufacture of an iron-aluminum intermetallic alloy, to an iron-aluminum intermetallic alloy which can be obtained by said process, and to an element constituted of such an alloy.

Les alliages intermétalliques fer-aluminium présentent, par rapport aux autres alliages structuraux, des propriétés particulières qui sont une faible densité et une résistance spécifique, c'est-à-dire une propriété rapportée à la densité du matériau, élevée comparée aux aciers et aux superalliages. Ils présentent par exemple une rigidité spécifique élevée comparée aux alliages légers, aux aciers et aux alliages de nickel, une ductilité élevée comparée à celle des autres intermétalliques tels que TiAl et NiAl, une résistance mécanique élevée jusqu'à 700°C par rapport aux alliages d'aluminium et aux composites à matrice organique, une résistance à la corrosion sèche élevée par rapport à la plupart des aciers et superalliages inoxydables, et un faible coût des matériaux de base.Iron-aluminum intermetallic alloys present, compared to other alloys structural, particular properties which are a low density and specific resistance, i.e. a property related to the density of the material, high compared to steels and superalloys. They for example have a high specific rigidity compared to light alloys, steels and nickel alloys, high ductility compared to that of other intermetallics such as TiAl and NiAl, high mechanical resistance up to 700 ° C by compared to aluminum alloys and composites organic matrix, resistance to dry corrosion high compared to most steels and stainless superalloys, and low cost of basic materials.

L'ensemble de ces propriétés permet de considérer ces alliages comme des substituts possibles aux alliages légers, aux aciers ou aux superalliages, pour des applications industrielles exploitant leurs propriétés particulières. En effet, une densité réduite de 25% par rapport aux aciers et alliages de nickel, pour des propriétés et moyens de mise en oeuvre comparables par ailleurs, permet d'envisager une réduction de poids de pièces structurales aéronautiques et spatiales telles que des pièces de boulonnerie, des trains d'atterrissage, des pièces de systèmes de freinage, etc... La résistance spécifique élevée de ces alliages permet également d'envisager les applications en substitution d'alliages à haute résistance tels des aciers et superalliages, utilisés pour la fabrication de pièces critiques en mouvement de moteur thermique et de turbomachines, tels que des soupapes, des axes et arbres, des aubes de turbine. La réduction de masse de tels composants réduit généralement les problèmes d'inertie, de frottement et de vibrations, et entraíne de ce fait une possible réduction de masse d'autres composants tels que des paliers, des ressorts, des systèmes d'attache et de refroidissement, intervenant dans les mouvements de ces pièces critiques.All of these properties make it possible to consider these alloys as possible substitutes for light alloys, steels or superalloys, for industrial applications exploiting their special properties. Indeed, a reduced density 25% compared to nickel steels and alloys, for properties and means of implementation comparable, allows to consider a weight reduction of aeronautical structural parts and spatial such as hardware, undercarriages, parts of systems braking, etc. The high specific resistance of these alloys also allows considering applications replacing high-strength alloys such as steels and superalloys, used for manufacturing critical parts in motion of the heat engine and turbomachinery, such as valves, shafts and trees, turbine blades. Mass reduction of such components generally reduces the problems of inertia, friction and vibration, and drives thereby a possible reduction in mass of others components such as bearings, springs, fastening and cooling systems, involved in the movements of these critical pieces.

La rigidité spécifique constitue une propriété particulièrement intéressante de ces matériaux. Elle est en effet de 10 à 20% plus élevée que celle des alliages structuraux utilisés actuellement tels que les alliages légers, les aciers et les superalliages, pour la fabrication de pièces devant travailler dans des régimes vibratoires proches de limite de résonance, voire au-delà, tels que certains arbres de puissance de turbine ou certaines buses ou canalisations d'injection de fluide.Specific stiffness is a property particularly interesting of these materials. She is in fact 10 to 20% higher than that of structural alloys currently used such as light alloys, steels and superalloys, for the manufacture of parts that must work in vibratory regimes close to resonance limit, or even beyond, such as certain power trees of turbine or certain injection nozzles or pipes of fluid.

Les propriétés de résistance à la corrosion de ces alliages leur permettent d'être utilisés pour la fabrication de résistors de four ou de tubes d'échangeur de chaleur. The corrosion resistance properties of these alloys allow them to be used for the manufacture of furnace resistors or tubes heat exchanger.

Etat de la techniqueState of the art

Dans un domaine de composition compris entre 25 à 50% d'aluminium, un alliage intermétallique fer-aluminium présente une phase cristalline ordonnée de structures cubiques centrées de type B2. Cette phase ordonnée, appelée encore première phase, possède une excellente résistance en environnement oxydant, sulfurant ou carburant, jusqu'à 1000°C, et une bonne résistance à l'érosion. Mais elle présente cependant une grande fragilité à température ambiante et une limite élastique et une résistance au fluage, peu élevées à haute température.In a composition range between 25 to 50% aluminum, an iron-aluminum intermetallic alloy has an ordered crystal phase of centered cubic structures of type B2. This phase ordered, also called first phase, has a excellent resistance in an oxidizing environment, sulfur or fuel, up to 1000 ° C, and good resistance to erosion. But it does, however, great fragility at room temperature and yield strength and creep resistance, little high at high temperature.

Les alliages intermétalliques fer-aluminium sont actuellement fabriqués par des procédés d'extrusion, à partir de mélanges de poudre comprenant essentiellement du fer et de l'aluminium.Iron-aluminum intermetallic alloys are currently manufactured by extrusion processes, from powder mixtures essentially comprising iron and aluminum.

De nombreuses recherches ayant pour but d'améliorer la résistance et la ductilité des alliages intermétalliques fer-aluminium obtenus par extrusion ont été effectuées. Ces recherches ont essentiellement porté sur la composition des poudres utilisées pour la fabrication de ces alliages et sur la granulométrie de ces poudres pour obtenir par extrusion un alliage intermétallique fer-aluminium ductile et résistant.A lot of research aimed at improve the strength and ductility of alloys iron-aluminum intermetallics obtained by extrusion have been performed. This research has essentially focused on the composition of the powders used for the manufacture of these alloys and on the particle size of these powders to obtain an alloy by extrusion ductile and resistant iron-aluminum intermetallic.

Ainsi, il a été montré que la phase cristalline ordonnée de cet alliage supporte l'addition de divers éléments supplémentaires qui renforcent les propriétés mécaniques de l'alliage. Ces éléments supplémentaires peuvent être par exemple du nickel, du cobalt, du titane, du magnésium, du zirconium, du bore, du chrome, du cérium ou un mélange de ces éléments, etc... dans des proportions et en combinaison variables. So, it has been shown that the crystalline phase ordinate of this alloy supports the addition of various additional elements which reinforce the properties alloy mechanics. These additional elements can be for example nickel, cobalt, titanium, magnesium, zirconium, boron, chromium, cerium or a mixture of these elements, etc ... in varying proportions and combinations.

Il a également été montré qu'il est possible de renforcer un tel alliage en y introduisant en plus des éléments supplémentaires précédemment cités, des dispersoïdes, c'est-à-dire des particules dites de seconde phase, très fines et bien dispersées d'oxydes très stables tels que par exemple Al2O3, Fe2O3, ou Y2O3.It has also been shown that it is possible to reinforce such an alloy by introducing therein, in addition to the additional elements previously mentioned, dispersoids, that is to say particles said to be of second phase, very fine and well dispersed. very stable oxides such as, for example, Al 2 O 3 , Fe 2 O 3 , or Y 2 O 3 .

La fabrication de ces alliages intermétalliques fer-aluminium par extrusion présente cependant un certain nombre d'inconvénients qui sont notamment un coût élevé, et une forte réduction de section des pièces fabriquées lors de l'extrusion, ce qui limite considérablement les dimensions diamétrales de ces pièces. Un autre inconvénient est que les alliages intermétalliques fer-aluminium sont difficiles à usiner, et lorsque la forme des pièces à fabriquer s'éloigne par exemple d'une forme de cylindre, celle-ci peut requérir un usinage important.The manufacture of these intermetallic alloys iron-aluminum by extrusion however has a number of drawbacks which include a high cost, and a large reduction in cross section of parts produced during extrusion, which limits considerably the diametrical dimensions of these rooms. Another disadvantage is that the alloys iron-aluminum intermetallics are difficult to machine, and when the shape of the parts to be manufactured moves away for example from a cylinder shape, this one may require significant machining.

Exposé de l'inventionStatement of the invention

L'invention a précisément pour but de fournir un procédé de fabrication d'un alliage intermétallique fer-aluminium présentant un coût de fabrication de l'alliage nettement inférieur à celui entraíné par un procédé d'extrusion. De plus, le procédé de l'invention permet de fabriquer un alliage présentant une résistance mécanique élevée et une ductilité suffisante pour de nombreuses applications.The object of the invention is precisely to provide a process for manufacturing an intermetallic alloy iron-aluminum with a manufacturing cost of the alloy clearly inferior to that entrained by a extrusion process. In addition, the method of the invention used to manufacture an alloy having a high mechanical strength and sufficient ductility for many applications.

Le procédé de fabrication d'un alliage intermétallique fer-aluminium selon l'invention comprend les étapes suivantes :

  • préparation d'une poudre de granulométrie déterminée à partir d'un mélange comprenant du fer et de l'aluminium,
  • un dégazage de ladite poudre, et
  • une compression à chaud de la poudre dégazée de manière à obtenir un alliage intermétallique fer-aluminium.
The process for manufacturing an iron-aluminum intermetallic alloy according to the invention comprises the following steps:
  • preparation of a powder of determined particle size from a mixture comprising iron and aluminum,
  • degassing of said powder, and
  • hot compression of the degassed powder so as to obtain an iron-aluminum intermetallic alloy.

Selon l'invention, la poudre peut comprendre en outre un élément choisi parmi du nickel, du cobalt, du titane, du magnésium, du zirconium, du bore, du chrome, du cérium, ou un mélange de ces éléments.According to the invention, the powder can comprise in in addition to an element chosen from nickel, cobalt, titanium, magnesium, zirconium, boron, chromium, cerium, or a mixture of these.

Selon l'invention, la poudre peut comprendre par exemple de 20 à 50% en poids d'aluminium, et peut comprendre en outre de 0,05 à 0,5% en poids de zirconium, de 0,001 à 0,02% en poids de bore, le reste étant du fer et des impuretés inévitables.According to the invention, the powder can comprise by example of 20 to 50% by weight of aluminum, and can further comprise from 0.05 to 0.5% by weight of zirconium, from 0.001 to 0.02% by weight of boron, the rest being inevitable iron and impurities.

Selon l'invention, la poudre peut comprendre environ 21 à 28% en poids d'aluminium, et peut comprendre en outre environ 0,08 à environ 0,14% en poids de zirconium, environ 0,012 à environ 0,018% en poids de bore, le reste étant du fer et des impuretés inévitables.According to the invention, the powder can comprise about 21 to 28% by weight of aluminum, and can further include about 0.08 to about 0.14% in weight of zirconium, about 0.012 to about 0.018% by weight of boron, the rest being iron and impurities inevitable.

Selon l'invention, la granulométrie de la poudre peut être comprise dans une plage allant de 10 à 500 µm, de préférence dans une plage allant de 10 à 50 µm.According to the invention, the particle size of the powder can be in the range of 10 to 500 µm, preferably in a range from 10 to 50 µm.

Selon l'invention, le procédé peut comprendre en outre une étape de dispersion dans la poudre d'un oxyde choisi parmi Y2O3, Al2O3, Fe2O3, ou d'un mélange de ces oxydes, sous forme d'une poudre nanométrique.According to the invention, the method can also comprise a step of dispersing in the powder an oxide chosen from Y 2 O 3 , Al 2 O 3 , Fe 2 O 3 , or a mixture of these oxides, in the form of a nanometric powder.

Selon l'invention, le procédé peut comprendre en outre une étape de dispersion dans la poudre d'environ 0,5 à environ 1,5% en poids de Y2O3 sous forme d'une poudre nanométrique, de préférence environ 1% en poids de Y2O3. According to the invention, the method can also comprise a step of dispersing in the powder from about 0.5 to about 1.5% by weight of Y 2 O 3 in the form of a nanometric powder, preferably about 1% by weight of Y 2 O 3 .

Selon l'invention, la poudre peut être préparée par un broyage à sec dudit mélange sous un gaz neutre. Ce broyage à sec peut être réalisé par exemple dans un broyeur à boulets.According to the invention, the powder can be prepared by dry grinding said mixture under a neutral gas. This dry grinding can be carried out for example in a ball mill.

Selon l'invention, la poudre est ensuite dégazée par exemple au moyen d'une pompe à vide.According to the invention, the powder is then degassed for example by means of a vacuum pump.

Selon l'invention, la compression à chaud de la poudre dégazée peut être effectuée à une température allant d'environ 900 à environ 1300°C, de préférence à une température allant d'environ 1000 à environ 1200°C.According to the invention, the hot compression of the degassed powder can be made at a temperature ranging from about 900 to about 1300 ° C, preferably a temperature ranging from approximately 1000 to approximately 1200 ° C.

Selon l'invention, la compression à chaud de la poudre dégazée peut être effectuée à une pression allant d'environ 50 à environ 400 MPa, de préférence à une pression d'environ 100 MPa.According to the invention, the hot compression of the degassed powder can be made at a pressure ranging from about 50 to about 400 MPa, preferably at a pressure of about 100 MPa.

Selon l'invention, la compression de la poudre peut être effectuée à pression variable ou à pression isostatique.According to the invention, the compression of the powder can be performed at variable pressure or pressure isostatic.

Selon l'invention, on peut effectuer la compression pendant une durée allant d'environ 0,5 à environ 4 heures, de préférence pendant une durée d'environ 2 heures.According to the invention, the compression for a period ranging from about 0.5 to about 4 hours, preferably for a period about 2 hours.

L'invention se rapporte également à un alliage intermétallique fer-aluminium pouvant être obtenu par le procédé de l'invention, ledit alliage comprenant du fer, de l'aluminium, du zirconium, du bore, et de l'oxyde d'yttrium, et présentant un allongement d'environ 1,5% et une limite élastique d'environ 960 MPa.The invention also relates to an alloy iron-aluminum intermetallic obtainable by the method of the invention, said alloy comprising iron, aluminum, zirconium, boron, and yttrium oxide, and having an elongation about 1.5% and an elastic limit of about 960 MPa.

L'invention se rapporte également à un alliage intermétallique fer-aluminium pouvant être obtenu par le procédé de l'invention, ledit alliage comprenant du fer, de l'aluminium, du zirconium, du bore, et de l'oxyde d'yttrium et présentant un allongement d'environ 0,2 à environ 0,8% et une limite élastique d'environ 1240 MPa.The invention also relates to an alloy iron-aluminum intermetallic obtainable by the method of the invention, said alloy comprising iron, aluminum, zirconium, boron, and yttrium oxide and having an elongation from about 0.2 to about 0.8% and an elastic limit about 1240 MPa.

L'invention consiste donc notamment à densifier une poudre de granulométrie déterminée à partir d'un mélange comprenant du fer et de l'aluminium, au moyen d'un pressage à chaud.The invention therefore consists in particular in densifying a powder with a particle size determined from a mixture comprising iron and aluminum, by means hot pressing.

De façon surprenante, l'alliage dense obtenue par ce procédé présente des propriétés tout à fait surprenantes pour de nombreuses applications. Cet alliage présente en particulier une résistance mécanique pouvant atteindre ou dépasser 1000 MPa et une ductilité pouvant dépasser 1%.Surprisingly, the dense alloy obtained by this process has properties quite surprising for many applications. This alloy in particular has resistance mechanical can reach or exceed 1000 MPa and a ductility which can exceed 1%.

De plus, le procédé de l'invention ne présente pas les inconvénients précités des procédés d'extrusion de l'art antérieur.In addition, the method of the invention does not have the aforementioned drawbacks of the extrusion processes of prior art.

La présente invention permet en outre de fabriquer des éléments en alliage intermétallique fer-aluminium de grandes dimensions. En effet, la compression de la poudre dégazée peut être réalisée dans un conteneur ou moule pouvant aller par exemple jusqu'à 1 mètre de diamètre et 2 mètres de hauteur, sans que ces limites soient absolues, pour obtenir un élément en alliage intermétallique fer-aluminium ayant sensiblement les mêmes dimensions que le conteneur.The present invention further makes it possible to manufacture elements of iron-aluminum intermetallic alloy large dimensions. Indeed, the compression of the degassed powder can be made in a container or mold can go for example up to 1 meter diameter and 2 meters in height, without these limits are absolute, to obtain an alloy element iron-aluminum intermetallic having substantially the same dimensions as the container.

De plus, le conteneur ou moule peut avoir une forme complexe pour réaliser des éléments en alliage intermétallique fer-aluminium de forme complexe sans forcément avoir recours à un usinage.In addition, the container or mold may have a complex shape for making alloy elements iron-aluminum intermetallic complex shape without necessarily have to resort to machining.

Le procédé de l'invention permet en outre de fabriquer des éléments en alliage intermétallique fer-aluminium près des cotes ou aux cotes, c'est-à-dire que les pièces ainsi fabriquées ne nécessitent pas, ou peu, d'usinage ultérieur. The method of the invention also makes it possible to manufacture elements from an iron-aluminum intermetallic alloy near the odds or the odds, that is to say that the parts thus manufactured do not require, or little, subsequent machining.

Il existe en conséquence de nombreux exemples d'application de l'invention à la fabrication d'éléments ou pièces en alliage intermétallique fer-aluminium.There are therefore many examples of application of the invention to manufacturing of elements or parts made of iron-aluminum intermetallic alloy.

Parmi eux, on peut citer par exemple sans être limitatif :

  • la fabrication de pièces structurales automobiles, aéronautiques et spatiales : boulonneries, trains d'atterrissage, pièces de systèmes de freinage, etc...
  • la fabrication de pièces critiques en mouvement de moteurs thermiques et de turbomachines, tels que les soupapes, les axes et arbres, les vilebrequins et pistons, les aubes de turbine ;
  • la fabrication de pièces devant travailler dans des régimes vibratoires proches de limites de résonance, voire au-delà telles que certains arbres de puissance de turbines ou certaines buses ou canalisations d'injection de fluides ;
  • la fabrication de résistors de fours ou de tubes d'échangeurs de chaleur ou de pièces soumises à des conditions difficiles de corrosion sèche.
Among them, we can cite for example without being limiting:
  • the manufacture of automotive, aeronautical and space structural parts: bolts, landing gear, braking system parts, etc.
  • the manufacture of critical moving parts of heat engines and turbomachines, such as valves, shafts and shafts, crankshafts and pistons, turbine blades;
  • the manufacture of parts having to work in vibratory regimes close to resonance limits, or even beyond such as certain power shafts of turbines or certain nozzles or pipes for injecting fluids;
  • the manufacture of furnace resistors or heat exchanger tubes or parts subjected to difficult conditions of dry corrosion.

L'exposé de l'invention est ci-après illustré par un mode de réalisation donné à titre d'exemple non limitatif.The description of the invention is illustrated below by an embodiment given by way of example not limiting.

Exemple 1Example 1

Dans une première étape du procédé de l'invention, une poudre de granulométrie déterminée est préparée à partir d'un mélange comprenant 24% en poids d'aluminium, 0,11% de zirconium, 0,0026% en poids de bore, le reste étant du fer et des impuretés inévitables. Ce mélange est mis en fusion pour être coulé sous forme de lingots.In a first step of the process of the invention, a powder of determined particle size is prepared for from a mixture comprising 24% by weight aluminum, 0.11% zirconium, 0.0026% by weight of boron, the balance being iron and impurities inevitable. This mixture is melted to be cast in the form of ingots.

Ces lingots sont ensuite atomisés sous argon afin d'obtenir une poudre pré-alliée fine et sphérique.These ingots are then atomized under argon so to obtain a fine and spherical pre-alloyed powder.

Cette poudre pré-alliée est ensuite broyée à sec sous argon dans un broyeur à boulet, en ajoutant au début du broyage 1% en poids de Y2O3.This pre-alloyed powder is then ground dry under argon in a ball mill, adding at the start of the milling 1% by weight of Y 2 O 3 .

Une poudre de granulométrie comprise entre 50 et 300 est obtenue.A powder with a particle size between 50 and 300 is obtained.

Toutes les étapes de cet exemple sont réalisées dans des conditions permettant de limiter la contamination par l'atmosphère ou par des inclusions exogènes.All the steps in this example are carried out under conditions that limit the contamination by the atmosphere or by inclusions exogenous.

L'opération de broyage introduit une quantité d'environ 0,03% en poids d'oxygène et d'environ 0,01% en poids de carbone dans l'alliage. Le carbone provient de l'usure des billes du broyeur à boulets au cours du broyage.The grinding operation introduces a quantity about 0.03% by weight of oxygen and about 0.01% by weight of carbon in the alloy. Carbon comes wear of the balls in the ball mill during grinding.

La poudre broyée est mise dans un conteneur et densifiée par compression isostatique à chaud à une température de 1100°C sous une pression de 100 MPa pendant 2 heures.The ground powder is put in a container and densified by hot isostatic compression at a temperature of 1100 ° C under a pressure of 100 MPa during 2 hours.

Une pièce en alliage intermétallique près des cotes ou aux cotes est obtenue.An intermetallic alloy part near the odds or odds is obtained.

Les propriétés mécaniques de l'alliage obtenu ont été déterminées dans les conditions les moins favorables à la ductilité d'un tel alliage, c'est-à-dire sur une pièce usinée non polie, sous air déshydraté et à une vitesse de traction faible.The mechanical properties of the alloy obtained have been determined under the least conditions favorable to the ductility of such an alloy, that is to say on an unpolished machined part, in air dehydrated and at a low traction speed.

Les avantages en termes de résistance mécanique et de ductilité sont très nets. En particulier, cet alliage présente un allongement de 1,5% et une limite élastique de 960 MPa à température ambiante. The advantages in terms of mechanical resistance and of ductility are very clear. In particular, this alloy has an elongation of 1.5% and a limit elastic of 960 MPa at room temperature.

Exemple 2Example 2

A partir d'une poudre identique à celle préparée dans l'exemple 1, et dans les mêmes conditions, la poudre broyée est mise dans un conteneur et densifiée par compression isostatique à chaud à une température de 1000°C et sous une pression isostatique de 100 MPa pendant 2 heures.From a powder identical to that prepared in Example 1, and under the same conditions, the crushed powder is put in a container and densified by hot isostatic compression at a temperature of 1000 ° C and under an isostatic pressure of 100 MPa during 2 hours.

Une pièce en alliage intermétallique fer-aluminium près des cotes ou aux cotes est obtenue.A piece of iron-aluminum intermetallic alloy near the odds or odds is obtained.

Cet alliage présente un allongement de 0,2 à 0,8% et une limite élastique de 1240 MPa.This alloy has an elongation of 0.2 to 0.8% and an elastic limit of 1240 MPa.

Claims (19)

Procédé de fabrication d'un alliage intermétallique fer-aluminium comprenant les étapes suivantes : une préparation d'une poudre de granulométrie déterminée à partir d'un mélange comprenant du fer et de l'aluminium, un dégazage de ladite poudre, et une compression à chaud de la poudre dégazée de manière à obtenir l'alliage intermétallique fer-aluminium. Method for manufacturing an iron-aluminum intermetallic alloy comprising the following steps: a preparation of a powder of determined particle size from a mixture comprising iron and aluminum, degassing of said powder, and hot compression of the degassed powder so as to obtain the iron-aluminum intermetallic alloy. Procédé selon la revendication 1, dans lequel la poudre comprend en outre un élément choisi parmi du nickel, du cobalt, du titane, du magnésium, du zirconium, du bore, du chrome, du cérium ou un mélange de ces éléments.The method of claim 1, wherein the powder also comprises an element chosen from nickel, cobalt, titanium, magnesium, zirconium, boron, chromium, cerium or a mixture of these elements. Procédé selon la revendication 1, dans lequel la poudre comprend de 20 à 50% en poids d'aluminium, et comprend en outre de 0,05 à 0,5% en poids de zirconium, de 0,001 à 0,02% en poids de bore, le reste étant du fer et des impuretés inévitables.The method of claim 1, wherein the powder comprises from 20 to 50% by weight of aluminum, and further comprises from 0.05 to 0.5% by weight of zirconium, from 0.001 to 0.02% by weight of boron, the remainder being iron and unavoidable impurities. Procédé selon la revendication 1, dans lequel la poudre comprend environ 21 à 28% en poids d'aluminium et comprend en outre environ 0,08 à environ 0,14% en poids de zirconium, environ 0,012 à environ 0,018% en poids de bore, le reste étant du fer et des impuretés inévitables. The method of claim 1, wherein the powder comprises approximately 21 to 28% by weight aluminum and further includes about 0.08 to about 0.14% by weight of zirconium, approximately 0.012 to approximately 0.018% by weight of boron, the rest being iron and unavoidable impurities. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel la granulométrie de la poudre est comprise dans une plage allant de 10 à 500 µm.Method according to any one of claims 1 to 4, wherein the particle size of the powder is in a range from 10 to 500 µm. Procédé selon l'une quelconque des revendications 1 à 5, comprenant en outre une étape de dispersion dans la poudre d'un oxyde choisi parmi Y2O3, Al2O3, Fe2O3, ou d'un mélange de ces oxydes, sous forme d'une poudre nanométrique.Process according to any one of Claims 1 to 5, further comprising a step of dispersing in the powder an oxide chosen from Y 2 O 3 , Al 2 O 3 , Fe 2 O 3 , or a mixture of these oxides, in the form of a nanometric powder. Procédé selon l'une quelconque des revendications 1 à 5, comprenant en outre une étape de dispersion dans la poudre d'environ 0,5 à environ 1,5% en poids de Y2O3 sous forme d'une poudre nanométrique.A method according to any one of claims 1 to 5, further comprising a step of dispersing in the powder from about 0.5 to about 1.5% by weight of Y 2 O 3 in the form of a nanometric powder. Procédé selon l'une quelconque des revendications 1 à 7, dans lequel la poudre est préparée par un broyage à sec dudit mélange sous un gaz neutre.Method according to any one of claims 1 to 7, wherein the powder is prepared by dry grinding said mixture under a gas neutral. Procédé selon la revendication 8, dans lequel le broyage à sec est réalisé dans un broyeur à boulets.The method of claim 8, wherein dry grinding is carried out in a ball mill. Procédé selon l'une quelconque des revendications précédentes, dans lequel on effectue la compression à chaud à une température allant d'environ 900 à environ 1300°C.Method according to any one of previous claims, in which the hot compression at a temperature of about 900 at around 1300 ° C. Procédé selon l'une quelconque des revendications précédentes, dans lequel on effectue la compression à chaud à une température allant d'environ 1000 à environ 1200°C. Method according to any one of previous claims, in which the hot compression at a temperature of about 1000 to about 1200 ° C. Procédé selon l'une quelconque des revendications précédentes, dans lequel on effectue la compression à une pression allant d'environ 50 à environ 400 MPa.Method according to any one of previous claims, in which the compression at a pressure ranging from about 50 to about 400 MPa. Procédé selon l'une quelconque des revendications 1 à 11, dans lequel on effectue la compression à une pression d'environ 100 MPa.Method according to any one of claims 1 to 11, in which the compression at a pressure of about 100 MPa. Procédé selon l'une quelconque des revendications 1 à 13, dans lequel on effectue la compression sous pression isostatique.Method according to any one of claims 1 to 13, in which the compression under isostatic pressure. Procédé selon l'une quelconque des revendications 1 à 14, dans lequel on effectue la compression pendant une durée allant d'environ 0,5 à environ 4 heures.Method according to any one of claims 1 to 14, in which the compression for a period ranging from about 0.5 to about 4 hours. Procédé selon l'une quelconque des revendications 1 à 14, dans lequel on effectue la compression pendant une durée de 2 heures.Method according to any one of claims 1 to 14, in which the compression for a period of 2 hours. Alliage intermétallique fer-aluminium comprenant du fer, de l'aluminium, du zirconium, du bore et de l'oxyde d'yttrium, ledit alliage présentant un allongement d'environ 1,5% et une limite élastique d'environ 960 MPa, ledit alliage pouvant être obtenu par le procédé selon la revendication 6 ou 7.Iron-aluminum intermetallic alloy including iron, aluminum, zirconium, boron and yttrium oxide, said alloy having an elongation of about 1.5% and an elastic limit about 960 MPa, said alloy obtainable by the method according to claim 6 or 7. Alliage intermétallique fer-aluminium comprenant du fer, de l'aluminium, du zirconium, du bore, et de l'oxyde d'yttrium, ledit alliage présentant un allongement d'environ 0,2 à environ 0,8% et une limite élastique d'environ 1240 MPa, ledit alliage pouvant être obtenu par le procédé selon la revendication 6 ou 7.Iron-aluminum intermetallic alloy including iron, aluminum, zirconium, boron, and yttrium oxide, said alloy having an elongation of about 0.2 to about 0.8% and a elastic limit of around 1240 MPa, said alloy obtainable by the process according to the claim 6 or 7. Elément en alliage intermétallique fer-aluminium obtenu par un procédé selon l'une quelconque des revendications 1 à 16.Iron-aluminum intermetallic alloy element obtained by a process according to any one of claims 1 to 16.
EP99400282A 1998-02-10 1999-02-08 Process for producing an iron-aluminium intermetallic alloy and iron-aluminium intermetallic alloy Ceased EP0936277A1 (en)

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AU2022224725B2 (en) * 2021-08-31 2023-09-21 Kunming University Of Science And Technology Preparation method of in-situ synthesized zirconia toughened alumina (ZTA) ceramic particles-reinforced steel matrix structural composite

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AU2022224725B2 (en) * 2021-08-31 2023-09-21 Kunming University Of Science And Technology Preparation method of in-situ synthesized zirconia toughened alumina (ZTA) ceramic particles-reinforced steel matrix structural composite

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