WO2004014586A2 - Fabrication de poudres contenant des agents auxiliaires de compression - Google Patents

Fabrication de poudres contenant des agents auxiliaires de compression Download PDF

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Publication number
WO2004014586A2
WO2004014586A2 PCT/EP2003/008489 EP0308489W WO2004014586A2 WO 2004014586 A2 WO2004014586 A2 WO 2004014586A2 EP 0308489 W EP0308489 W EP 0308489W WO 2004014586 A2 WO2004014586 A2 WO 2004014586A2
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powder
pressing
powders
mixture
mixed
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WO2004014586A8 (fr
WO2004014586A3 (fr
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Benno Gries
Bernhard Szesny
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    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/56—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides
    • C04B35/5607—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on refractory metal carbides
    • C04B35/5626—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbides or oxycarbides based on refractory metal carbides based on tungsten carbides
    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • 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
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/10—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
    • B22F1/108—Mixtures obtained by warm mixing
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/62605—Treating the starting powders individually or as mixtures
    • C04B35/62625—Wet mixtures
    • C04B35/62635—Mixing details
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/622—Forming processes; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/626—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B
    • C04B35/63—Preparing or treating the powders individually or as batches ; preparing or treating macroscopic reinforcing agents for ceramic products, e.g. fibres; mechanical aspects section B using additives specially adapted for forming the products, e.g.. binder binders
    • C04B35/632—Organic additives
    • 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
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/40—Metallic constituents or additives not added as binding phase
    • C04B2235/405—Iron group metals
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/50—Constituents or additives of the starting mixture chosen for their shape or used because of their shape or their physical appearance
    • C04B2235/54—Particle size related information
    • C04B2235/5418—Particle size related information expressed by the size of the particles or aggregates thereof
    • C04B2235/5445—Particle size related information expressed by the size of the particles or aggregates thereof submicron sized, i.e. from 0,1 to 1 micron

Definitions

  • a uniform press density is particularly critical when the sintered part is to have a defined, locally homogeneous and open porosity, or is sintered in the final contour because no rework is to be carried out, or the pressing, also called green body, is special during further handling or processing is exposed to mechanical loads.
  • the former is important, for example, with sintered metal filter elements, tantalum sintered anodes for capacitors, but also with other sintered parts that are later to be infiltrated. In the latter applications, infiltration takes place, for example with bronze, strontium titanate or copper. Applications are in the area of WCu composites, UV lamp electrodes or plain bearings etc.
  • an organic lubricant the so-called pressing aid
  • the most frequently used are pressing aids from the wax substance class, which can be decomposed without residue during the sintering process.
  • the selection of the right wax is based on physical and chemical criteria. As a rule of thumb, a wax with a low softening range has better lubricating properties and allows lower pressures with the same press density than one with a high softening range. However, the wax has too
  • Press pressure also the mechanical stability of the compact, since it must not be damaged when it is ejected from the mold or during further handling.
  • high press densities also mean high mechanical stability, which can be achieved by high press pressures.
  • the mechanical stability can be quantified by various methods such as chatillon tests or abrasion methods. With these processes, a press is produced under standardized conditions and its mechanical strength or mechanical abrasion is measured. In the latter case, compacts with a standardized weight are produced at standardized pressures and placed in a cylindrical wire basket which rotates about its longitudinal axis. After a predetermined number of revolutions, the weight of the tube basket including its contents weighed, and the percentage of abrasion is determined from the gross weight (so-called "rattler test"). The higher the abrasion resistance, the lower the abrasion at a given number of revolutions.
  • a high green strength is desirable from the point of view of production technology.
  • the press pressure due to the materials available for the press tool and the maximum achievable press force.
  • the pressing force used and thus the achievable density of the compact the so-called pressing density, is therefore limited.
  • An improved green strength can, however, be achieved by carrying out the shaping in such a way that the press density within the compact is as uniform as possible.
  • a non-uniform press density manifests itself, among other things, by high abrasion or low green strength, since poorly compressed areas have low strength.
  • a uniform press density should therefore lead to higher abrasion resistance of the green body with the same press pressure.
  • a high press density for sintered parts to be infiltrated later can prevent the control of the porosity after sintering.
  • the control of the content of infiltration agent in the infiltrated component is done by controlling the necessarily open porosity after sintering, which in turn can only be controlled indirectly via the porosity of the press body and thus the press density.
  • a low pressing density, which is necessary from the point of view of infiltration, can lead to such low green strengths that the compacts can no longer be handled without damage.
  • An object of the present invention is to solve this conflict of objectives between green density and green strength.
  • pressing aids into the starting powder happens industrially in different ways. Mixtures of different starting powders are often used so that powders have to be mixed with other powders before use or the powders are not fine enough and have to be ground. This often happens when wet, with the pressing aid dissolved in the grinding fluid. Spray drying is often carried out after the grinding process. This method is more suitable for ceramic powder. in the
  • Another method is the mixing of powdery pressing aids with the starting powders in a free-fall mixer, the powder being hardly mechanically loaded and therefore the particle size distribution or agglomerate size distribution is not changed significantly.
  • the free-fall mixer is an only partially filled, rotating container.
  • This process can also be carried out in a mixer equipped with circulating tools, e.g. a paddle mixer from Lödige. In this case, mixing of the metal powder with the powdered wax is achieved, but none
  • EP 0781 180 B1 describes a process for mixing metal powders based on iron with powdered polyethers, the mixing being carried out without the addition of solvents.
  • the key point is the use of the special pressing aid, which means that the green strength can be increased compared to the use of conventional pressing aids, for example a commercially available wax.
  • the powdered polyether is added in an amount of up to 10% by weight.
  • EP 0 968 068 B1 also discloses a special pressing aid for producing sinterable molded parts from metal powders.
  • the pressing aid contains polyethylene glycol with a molecular weight of 3000 to 6500 g mol and can, for example, be mixed with the starting powder in a drum mixer.
  • the drum mixer is heated to a temperature which is above the softening temperature of the pressing aid provided for the subsequent pressing process.
  • Powder mixed with the pressing aid in an intensive mixer until it reaches a temperature above the melting point of the pressing aid due to the energy input.
  • a drum mixer with circulating tools can be used, which is heated externally by means of a heating jacket. Very good wetting is achieved by the pressing aid.
  • the powder is mechanically stressed by this high energy input, so that agglomerated powders in particular are deagglomerated.
  • the capillary action of the molten pressing aid and the movement of the mixed material result in partial compaction and granulation of the mixed material. Powders produced in this way have a comparatively high bulk density. It is characteristic of the hot mixing that the powder bed for The melting aid of the pressing aid is in motion.
  • the pressing aid preferably wets a component when the melting point is reached, and granulate particles are formed which contain this powder component. This segregation is promoted by the mechanical movement of the mix.
  • Guaranteed powder with the pressing aid and the powder in terms of grain size distribution, grain shape and agglomeration state are not changed significantly.
  • Flowable products should be produced without organic solvents or water, and no segregation and / or granulation of powder components should be caused when mixing powder mixtures with the pressing aid.
  • the surprisingly simple solution now consists in briefly bringing the mixtures of starting powder and pressing aid produced at temperatures below the melting point of the pressing aid to a temperature above the
  • the invention therefore relates to a process for producing powders mixed with pressing aids, in a first step pulverulent pressing aids being mixed with a starting powder below the melting temperature of the pressing aid, and in a second step the mixture obtained from the first step to a temperature of at least the melting temperature of the pressing aid is heated, the mixture not moving during heating and subsequent cooling.
  • the method according to the invention can be carried out using the simplest of means.
  • the mixing of powdered pressing aid and starting powder is preferably carried out in a free-fall mixer.
  • Known mixers such as drum mixers or a partially filled, rotated container, for example a drum or a double cone mixer, can be used as free-fall mixers, for example.
  • a drum or compulsory mixer equipped with circulating tools can also be used. Regardless of the type of mixer used, it is essential that the melting point of the pressing aid is not reached during the mixing process.
  • the mixture obtained can be heated, for example, in a drying cabinet, a belt dryer or other suitable apparatus. It is essential that the mixture obtained is static during heating and cooling, i.e. is not moved in itself and that the mixing on the one hand and heating and cooling on the other hand are carried out in different units.
  • the process according to the invention is furthermore distinguished by the fact that neither organic solvents nor complex drying apparatuses, such as, for example, spray drying, are necessary.
  • the temperature during the heating corresponds at least to the melting temperature of the pressing aid.
  • the temperature is preferably 5 to 100 ° C. above the melting temperature of the pressing aid, particularly preferably 10 to 50 ° C.
  • heating to 50 to 250 ° C, preferably to 60 to 180 ° C, may be necessary.
  • the heat treatment is preferably carried out over a period of 0.1 to 10 h, particularly preferably from 0.5 to 2.2 h.
  • a characteristic of pressing aids, in particular waxes, is that they have a very low viscosity just above their melting point and can therefore completely wet the starting powder by capillary forces.
  • the powders produced in this way then accumulate in a bonded state, but rub on a sieve again to form smaller agglomerates without being ground, as a result of which good flowability is achieved.
  • Screening machine for example a tumble screening machine.
  • the size of the sieve openings depends essentially on the particle diameter of the powder mixed with pressing aids. For example, screen openings of 300 to 2000 ⁇ m have proven to be suitable.
  • the product in cake form is grated.
  • the powdery pressing aid is preferably used in an amount of 0.2 to 10% by weight, based on the total amount of pressing aid and starting powder, particularly preferably in an amount of 0.3 to 6% by weight, in particular preferably from 0.5 to 4% by weight.
  • any pressing aids can be used as powdered pressing aids, as long as they are available in solid, powdery form.
  • pressing aids from the group of the fatty acids or their metal salts, the fatty acid bisamides, the fatty acid monoamides, the fatty acid esters, the polyethylenes or their oxidic derivatives, and the waxes are mentioned, the use of waxes being preferred.
  • Zinc stearate, paraffin waxes and montan ester waxes are particularly preferably used.
  • micronized pressing aids with a particle diameter of a maximum of 5 to a maximum of 500 microns, ie from -5 to -500 ⁇ m, particularly preferably from a maximum of 10 to a maximum of 100 ⁇ m.
  • micronized pressing aids with a particle diameter of a maximum of 5 to a maximum of 500 microns, ie from -5 to -500 ⁇ m, particularly preferably from a maximum of 10 to a maximum of 100 ⁇ m.
  • These are preferably commercially available powders which have been sprayed from the melt, so that the grain size of the pressing aid corresponds to the droplet size when spraying.
  • pressing aids ground cryogenically in impact mills can also be used.
  • a large number of different starting powders can be used in the process according to the invention.
  • all ceramic or metallic powders or also composite powders, mixtures and alloys can be used.
  • metal powders or a mixture of metal powders or a mixture of metal powders with a carbide or oxide powder are preferably used.
  • Metal powders of tungsten, molybdenum, niobium and tantalum, but also of iron, cobalt, copper and nickel may be mentioned as examples of metal powder.
  • the metal powders can be in pure form. But it is also possible that they are in
  • Alloys are present or contain further additives, such as graphite, oxides or carbides, in particular tungsten carbide.
  • suitable alloy powders are tungsten-nickel alloys and tungsten carbide-cobalt alloys. Also to be mentioned are single and multi-phase alloy powders, alloy powders such as those e.g. can be used for tool steels, bearing and filter materials. It is also possible to use a mixture of alloy powders.
  • an oxidic powder is used as the starting powder
  • Powder a powder of a carbide or a mixture of carbide with metal powders is used.
  • the method according to the invention can be varied in addition to the production of
  • Powders can also be used to produce flowable granules, for example by heating the mixture produced in a free-fall mixer in motion in an aggregate suitable for building up granules.
  • This can be, for example, a continuous rotary tube dryer or a heatable pelletizing plate.
  • static heating of the powder is preferred, ie the powder is preferably not moved in itself during the heating. Cooling below the melting point of the pressing aid is also preferably static.
  • the mixture of powders with powdered pressing aid is very particularly preferably heated as a static, i.e. at rest, powder filling on a tray in a drying cabinet or on the belt of a
  • Belt dryer or in a glow box in an industrial furnace e.g. in a walking beam furnace or push-through furnace.
  • the metal powders mixed with pressing aids produced in the process according to the invention are particularly suitable for producing sinterable metallic
  • the invention therefore furthermore relates to a method for producing sinterable metallic moldings from metal powders mixed with pressing aids, powdered pressing aids containing a metal powder in a
  • the mean grain diameters given in the examples were determined using Fisher Sub Sieve Sizer (FSSS, ASTM B 330), the knock volume and knock density according to ASTM B 527 and the flowability using Hall Flow measurements
  • the powders were processed by uniaxial pressing at a pressing pressure of 6.7 t / cm 2 and placed in a cylindrical wire basket, which rotates about its longitudinal axis. After a predetermined number of revolutions, the weight of the wire basket and its contents were weighed, and the percentage of abrasion was determined from the gross weight (so-called “rattler test”). The higher the abrasion resistance, the lower the abrasion at a given number of revolutions. The abrasion test was carried out a commercially available device from Minerva Kiki Co. Ltd., Japan with the
  • the tungsten powder from Example 1 was mixed with 0.8% by weight of powdered zinc stearate for 2 hours in a stainless steel barrel. The flowability was then determined to be 4.3 s. The knock volume was 10.6 cm 3 / 100g. The press density was 14.52 g / cm 3 , the abrasion test, however, gave 100% abrasion after 150 revolutions. As the density improves, the strength of the compact deteriorates dramatically, making it difficult to handle the compact after it is ejected. In addition, there is poorer flowability of the powder obtained.
  • Example 3 (example according to the invention)
  • the tungsten metal powder from Example 2 mixed with 0.8% by weight of powdered zinc stearate was statically heated for 2 hours at 170 ° C. as a powder bed on a tray in a drying cabinet, and then statically cooled.
  • the cake obtained in this way was lightly ground on the 500 ⁇ m sieve fabric of a tumbler sieve machine (Allgaier type).
  • the tungsten metal powder thus obtained had the following properties:
  • a mixture of 3.8% by weight of nickel metal powder, 1.2% by weight of carbonyl iron powder and 95% by weight of tungsten metal powder (H.C. Starck GmbH, type HC
  • Example 4 Mixtures of the same type were produced with 1.5% by weight of powdered paraffin wax (melting point 57 ° C.) or with 1.5% by weight of a powdery montan ester wax (melting point 80 ° C), the proportions by weight of the other components being reduced proportionately (Examples 5 and 6). Pellets were produced from all powders as described in Example 1. The following table shows the values obtained with these powders:
  • the wax content lowers the flowability and the pressed density of the compact in example 5 increases in spite of the lower specific weight of the wax compared to example 4, since the wax reduces the internal friction and the wall friction during pressing. While the paraffin wax does not contribute to better abrasion resistance, the montan ester wax seems to improve it due to its polar character. When using montan ester wax, only a comparatively low pressing density is achieved, since this wax obviously cannot act as a pressing aid due to its comparatively high melting point, since the temperature increase during pressing does not suffice to reach the melting point of the wax.
  • Waxed mixtures which were obtained according to Examples 5 and 6, were statically heated in a drying cabinet as a powder bed on a tray tray for 1 h to temperatures above the melting point of the wax used (105 ° C.), again cooled statically, and the cake obtained was sieved on a 500 ⁇ m sieve.
  • the powder obtained in Example 7 contained wax wax with a melting point of 57 ° C, the powder obtained in Example 8 Montanesterwachs (melting point 80 ° C). Pellets were produced from the powders obtained as described in Example 1. The following values for the powder and pellet properties were obtained:
  • Example 8 is an example of a powder according to the invention which contains a wax which is optimized with regard to the flowability.
  • Examples 9 and 10 according to the invention)
  • the principle according to the invention is also effective in powder mixtures. With slightly poorer flowability, lower values for the tap density are achieved in comparison with the powder produced according to Example 10, which is an indicator of a rather loose structure of the powder pile. This is from This is an advantage when WCCo mixtures are to be processed into porous sintered agglomerates, such as those used in thermal spraying, or when shaping by pressing a uniform press density and thus a uniform shrinkage is required in order to be able to work close to the final contour and grinding work on the sintered Reduce fitting.
  • WC powder with an average grain diameter in accordance with FSSS of 5 ⁇ m and cobalt metal powder (CoMP IVC, HC Starck GmbH) with an average grain diameter in accordance with FSSS of 0.9 ⁇ m was, according to WO 00/42230 AI, into a 200 kg mixture with the composition 94% by weight. % WC and 6% by weight cobalt intensely mixed.
  • the powder components were mixed intensively in a mixer using both circulating tools and a rotor / stator system, the mixture being heated up considerably by the energy input.
  • Example 12 No significant temperature increase occurred (Example 12, according to the invention).
  • the material to be mixed was then poured onto a metallic drying tray as a powder bed and then heated statically in a drying cabinet at 80 ° C. for 1 hour. After the static cooling, the resulting cake was crushed through a 1 mm sieve and sieved over 315 ⁇ m, leaving no sieve residue.
  • the segregation effect observed in example 11 with the build-up of agglomerates therefore did not occur since the wax infiltration took place in a stationary powder bed.
  • the powder obtained according to the invention was also easy to disperse in liquid, since there was no coarse fraction which tended to sediment out. A dispersion obtainable in this way could be fed, for example, to a spray drying step in order to produce flowable granules without coarser parts being sedimented out during the production of the spray-dried dispersion of WCCo powder in liquid.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Ceramic Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Structural Engineering (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Powder Metallurgy (AREA)

Abstract

L'invention concerne un procédé de fabrication de poudres contenant des agents auxiliaires de compression, notamment des poudres métalliques. Le procédé selon l'invention consiste à mélanger un agent auxiliaire de compression pulvérulent avec une poudre initiale à une température située en dessous du point de fusion de l'agent auxiliaire de compression, et à chauffer le mélange ainsi obtenu à une température correspondant au moins à la température de fusion de l'agent auxiliaire de compression, ledit mélange ne subissant aucun mouvement lors du chauffage et du refroidissement successif. L'invention concerne également un procédé de fabrication de corps moulés métalliques frittables à partir de ces poudres contenant des agents auxiliaires de compression.
PCT/EP2003/008489 2002-08-02 2003-07-31 Fabrication de poudres contenant des agents auxiliaires de compression Ceased WO2004014586A2 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE10235413.8 2002-08-02
DE10235413A DE10235413A1 (de) 2002-08-02 2002-08-02 Herstellung Presshilfsmittel-haltiger Pulver

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WO2004014586A2 true WO2004014586A2 (fr) 2004-02-19
WO2004014586A8 WO2004014586A8 (fr) 2004-04-15
WO2004014586A3 WO2004014586A3 (fr) 2004-08-26

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Cited By (2)

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Publication number Priority date Publication date Assignee Title
DE102006045339B3 (de) * 2006-09-22 2008-04-03 H.C. Starck Gmbh Metallpulver
CN114450109A (zh) * 2019-09-25 2022-05-06 赢创运营有限公司 金属体及其制备方法

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EP0913220B1 (fr) * 1997-03-19 2008-12-10 JFE Steel Corporation Melange pulverise a base de fer destine a la metallurgie des poudres, dote d'excellentes caracteristiques de fluidite et d'aptitude au moulage
SE9703151D0 (sv) * 1997-09-01 1997-09-01 Hoeganaes Ab Lubricant for metallurgical powder compositions
US6517773B1 (en) * 1999-09-23 2003-02-11 Innovative Technology Licensing, Llc Direct metal fabrication of parts with surface features only

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102006045339B3 (de) * 2006-09-22 2008-04-03 H.C. Starck Gmbh Metallpulver
CN114450109A (zh) * 2019-09-25 2022-05-06 赢创运营有限公司 金属体及其制备方法
CN114450109B (zh) * 2019-09-25 2024-05-17 赢创运营有限公司 金属体及其制备方法

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