[go: up one dir, main page]

EP0800882A2 - Process for preparing granulate and articles from hard metal or cermet material - Google Patents

Process for preparing granulate and articles from hard metal or cermet material Download PDF

Info

Publication number
EP0800882A2
EP0800882A2 EP97105701A EP97105701A EP0800882A2 EP 0800882 A2 EP0800882 A2 EP 0800882A2 EP 97105701 A EP97105701 A EP 97105701A EP 97105701 A EP97105701 A EP 97105701A EP 0800882 A2 EP0800882 A2 EP 0800882A2
Authority
EP
European Patent Office
Prior art keywords
binder
hard material
material phase
granulate
metal powder
Prior art date
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.)
Withdrawn
Application number
EP97105701A
Other languages
German (de)
French (fr)
Other versions
EP0800882A3 (en
Inventor
Werner Dr. Hesse
Knut Dr. Bittler
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by BASF SE filed Critical BASF SE
Publication of EP0800882A2 publication Critical patent/EP0800882A2/en
Publication of EP0800882A3 publication Critical patent/EP0800882A3/en
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • B22F3/22—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip
    • B22F3/225—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces for producing castings from a slip by injection molding
    • 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
    • B22F1/103—Metallic powder containing lubricating or binding agents; Metallic powder containing organic material containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
    • 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
    • B22F3/10—Sintering only
    • B22F3/1017—Multiple heating or additional steps
    • B22F3/1021—Removal of binder or filler
    • B22F3/1025—Removal of binder or filler not by heating only
    • 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
    • C22C1/05—Mixtures of metal powder with non-metallic powder
    • C22C1/051—Making hard metals based on borides, carbides, nitrides, oxides or silicides; Preparation of the powder mixture used as the starting material therefor
    • 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
    • C22C1/05—Mixtures of metal powder with non-metallic powder
    • C22C1/059—Making alloys comprising less than 5% by weight of dispersed reinforcing phases
    • 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

Definitions

  • the present method relates to a method for producing molded parts by injection molding of granules which consist of a material mixture of a hard material phase, a metal powder and an organic binder, and a method for producing such granules.
  • Injection molded parts made of hard metal or cermet materials are produced by molding, debinding and sintering an injection molded granulate manufactured according to the needs of the individual case.
  • Such methods have been widely described in the literature, e.g. in EP-A 0 413 231, 0 444 475, 0 446 708 and 0 465 940.
  • the injection molding granulate is produced by mixing, for example kneading, a hard material phase and a metal component with an organic binder.
  • the metal component regularly consists of a so-called binding metal, which leads to better adhesion of the particles of the hard material phase to one another.
  • the metallic component and the hard phase have hitherto had to be mixed with one another before being mixed with the organic binder, in order later to obtain a homogeneous particle distribution in the granulate and, for example, to prevent the formation of "binder lakes”.
  • This premixing is usually carried out by Grinding, for example in ball mills, usually using a solvent such as alcohol. The need for premixing is described, for example, in EP-B 0 443 048 and EP-B 0 516 165.
  • the object of the present invention was therefore to provide a method for producing an injection molding granulate which is less technically complex, but which leads to comparably good results.
  • the homogeneity of the granules and the resulting advantageous material properties of the molded part should be preserved as far as possible.
  • At least one hard material phase is mixed with a metal powder and a binder and granulated with no premixing of the hard phase and the metal powder before mixing takes place with the binder and the binder has a viscosity of 20 to 200, preferably from 30 to 100 cm 3/10 min according to DIN 53735 at 195 ° C and 2.16 kg load weight.
  • the metal powder is a so-called binder metal powder, which improves the adhesion of the particles to one another.
  • Both the hard material phase and the metal phase can also consist of several different materials.
  • the granules can also contain organic additives for dispersion and surface modification.
  • wetting agents, plasticizers or other auxiliaries which influence the rheological properties of the granules during shaping can also be added to the granules.
  • the premixing step of the metal component and the hard material phase can, contrary to expectations, be omitted.
  • the flow properties of the granules during injection molding are also improved, as a result of which the shaping of complex parts is made considerably easier. Finally, the delivery time is significantly reduced.
  • the mixing of the metal component and the hard material phase with the binder can in principle be carried out by all known relevant processes. Typically, the components are extruded or kneaded at temperatures of 150 to 200 ° C., then cooled and granulated.
  • Binders which allow the premixing step to be dispensed with are, in particular, highly viscous binders which contain at least 70% by weight of at least one polyacetal, in particular of at least one polyoxymethylene or a polyoxymethylene homo- or copolymer consist of it.
  • the viscosity is the first component of the binder of 25 to 50 cm 3/10 min according to DIN 53735 at 195 ° C and 2.16 kg load weight, thus resulting in the specified overall viscosity of the binder.
  • Up to 30% by weight of further polymers can be used as the second component of the binder, preferably polybutanediol formal, polyethylene or polypropylene or a mixture of at least two of these polymers.
  • Polybutanediol formal preferably has a relative molar mass of 6,000 to 80,000.
  • Polyacetal binders which can be used with a suitable viscosity in the context of the invention have also been described in EP 413 231, EP 444 475, EP 446 708 and EP 465 940.
  • the volume fraction of the binder in the granules is preferably 30 to 70%.
  • a method is preferred in which a powder of at least one carbide, nitride or carbonitride of boron or a transition metal, in particular an element of group IVa, Va or VIa of the periodic table, is used as the hard material phase.
  • At least one element or alloy powder of an element from the group Fe, Co, Ni, Cr, Mo, W, preferably Co, Ni or Cr is preferably used as the metal powder.
  • Either the metal powder or the hard material phase or both powders preferably have an average grain size of less than 40 ⁇ m, preferably less than 20 ⁇ m.
  • a method for producing molded parts by injection molding in which a granulate which has been produced using one of the above methods is shaped, debindered and sintered.
  • the injection molded parts can be shaped by guiding the granules into molds using conventional screw or piston injection molding machines and at temperatures of typically 170 to 200.degree and is deformed at pressures between 200 and 2000 bar.
  • the binder is preferably removed from the shaped green body in an atmosphere which contains acid, in particular oxalic acid, or boron trifluoride. This applies above all to polyacetal binders of the type described above. For other binders, other debinding conditions may be more favorable.
  • the sintering is preferably carried out in an inert gas atmosphere, in a reducing atmosphere or in a vacuum.
  • sintering can also be carried out under increased inert gas pressure.
  • the sintering conditions must be tailored to the individual case, because these are of great importance for the correct setting of the carbon content in the molded part.
  • the carbon content in turn is of crucial importance for the material properties obtained.
  • a mixture of the following components was placed in a heatable kneader: 8,800 g of powdery WC which was doped with 0.1% by weight of NbC and had an average particle size of 2.2 ⁇ m; 1200 g of powdered Co with an average particle size of 1.6 microns; 40 g of polyethylene glycol with an average molecular weight of about 800; 35 g of polybutanediol formal with an average molecular weight of about 30,000; 850 g of polyoxymethylene with a proportion of 2% by weight of butanediol formal.
  • This mixture was melted at 175 ° C. and homogenized for one hour. It was then cooled and granulated. The granules had a Melt Flow Index according to DIN 53735, measured at 190 ° C and load of 10 kg weight, of 27 cm 3/10 min.
  • the granules were injection molded into moldings, which were then debindered in an oxalic acid / nitrogen gas atmosphere at 140 ° C.
  • the rate of debinding was 1 mm / h, i.e. with each hour of the debinding process, the molded green part became free of binder all around at a depth of 1 mm.
  • the three-point bending strength according to DIN ISO 3327 was 2200 MPa on samples "as fired".
  • a mixture of the following components was placed in a heatable kneader: 8,800 g of powdery WC, which was doped with 0.1% by weight of NbC and had an average particle size of 2.2 ⁇ m, and 1200 g of powdery Co with a average particle size of 1.6 ⁇ m; 600 g of montan ester wax, which was so low-viscosity that it was not possible to measure the melt flow index, and 60 g of low-density polyethylene (LDPE) were added as binders.
  • This mixture was melted at 120 ° C. and homogenized for one hour. It was then cooled and granulated. The granules had a Melt Flow Index according to DIN 53735, measured at 140 ° C and 2.16 kg load weight, of 21 cm 3/10 min.
  • This granulate was injection molded into molded parts.
  • the subsequent debinding was carried out as follows: heating the molded part in two steps, first to 350 ° C. at a rate of 10 K / h in a nitrogen atmosphere, then further to 650 ° C. at a rate of 50 K / h in vacuum (at most 0 , 7 mbar); Maintaining the temperature reached for 1 hour; Cooling down.
  • the debindered moldings were then sintered in an inert gas atmosphere at 1450 ° C. This gave moldings with a density of 13.9 g / ml.
  • the microstructure was not sufficiently homogeneous, "binding lakes” and pores were visible in microstructure images.
  • the three-point bending strength according to DIN-ISO 3327 was 1530 MPa for the samples "as fired”.
  • a mixture of 88% by weight WC powder and 12% by weight co-powder in alcohol was first wet-milled in a ball mill for 48 hours.
  • the powder mixture was then dried and, as in the example according to the invention above, processed together with the other components specified therein to give a granulate.
  • the Melt Flow Index of the granules was 16 cm 3/10 min, measured according to DIN 53735 at 190 ° C and 21.6 kg load weight.
  • the granules were injection molded as in the example according to the invention.
  • the molded green parts obtained were debindered under identical conditions as above, the speed being only 0.5 mm / h. After sintering, molded parts were obtained whose structure and properties were largely identical to the parts produced by the process according to the invention according to the example above.
  • Comparative example 2 shows that the process according to the invention can be used to produce homogeneous molded parts which do not require premixing, which are also easier to debinding and have good strength. It is also advantageous that the granulate produced by the process according to the invention is more flowable, which is the formation of complex parts facilitated. Comparative example 1, on the other hand, shows that the premixing in binders customary hitherto can only be omitted with considerable losses in the homogeneity and strength of the molded parts.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Mechanical Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Metallurgy (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dispersion Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Glanulating (AREA)
  • Adhesives Or Adhesive Processes (AREA)
  • Compositions Of Macromolecular Compounds (AREA)

Abstract

Preparation of a granulate by mixing at least one hard material phase (A) with a metal powder (B) and binder (C) and then granulating the mixture - carried out without any pre-mixing of (A) and (B) prior to mixing with (C), which has a viscosity of 20-200 (30-100) cm<3>/10 minutes at 195 degrees C and 2.16 kg load, according to DIN 53735. A process for making moulded articles by injection-moulding one of these granulates is also claimed, in which the granulate is shaped in a mould, binder is removed and then the material is sintered.

Description

Das vorliegende Verfahren betrifft ein Verfahren zur Herstellung von Formteilen durch Spritzgießen von Granulaten, die aus einem Materialgemisch aus einer Hartstoffphase, einem Metallpulver und einem organischen Bindemittel bestehen, sowie ein Verfahren zur Herstellung derartiger Granulate.The present method relates to a method for producing molded parts by injection molding of granules which consist of a material mixture of a hard material phase, a metal powder and an organic binder, and a method for producing such granules.

Spritzguß-Formteile aus Hartmetall- oder Cermet-Werkstoffen werden durch Formen, Entbindern und Versintern eines nach den Bedürfnissen des Einzelfalls hergestellten Spritzguß-Granulats hergestellt. Derartige Verfahren wurden in der Literatur vielfach beschrieben, z.B. in den EP-A 0 413 231, 0 444 475, 0 446 708 und 0 465 940.Injection molded parts made of hard metal or cermet materials are produced by molding, debinding and sintering an injection molded granulate manufactured according to the needs of the individual case. Such methods have been widely described in the literature, e.g. in EP-A 0 413 231, 0 444 475, 0 446 708 and 0 465 940.

Das Spritzguß-Granulat wird durch Mischen, z.B. Kneten, einer Hartstoffphase und einer Metallkomponente mit einem organischen Bindemittel hergestellt. Die Metallkomponente besteht dabei regelmäßig aus einem sogenannten Bindemetall, das zu einer besseren Haftung der Partikel der Hartstoffphase aneinander führt. Die metallische Komponente und die Hartstoffphase müssen bisher vor ihrer Vermischung mit dem organischen Bindemittel miteinander vermischt werden, um später eine homogene Partikelverteilung in dem Granulat zu erhalten und zum Beispiel die Bildung von "Bindemittelseen" zu verhindern. Diese Vorvermischung erfolgt üblicherweise durch Mahlung, z.B. in Kugelmühlen, wobei meistens ein Lösungsmittel wie Alkohol beigegeben wird. Die Notwendigkeit einer Vorvermischung wird zum Beispiel in EP-B 0 443 048 und EP-B 0 516 165 beschrieben. Durch die bei der Mahlung entstehende Wärme kommt es zu einem Aufschmieden der weicheren auf die härtere Komponente. Dies führt zu einer besonders dauerhaften homogenen Mischung der Komponenten. Dieser Aufschmiedeeffekt wird z.B. von D. R. Moyle, Proceedings of 1993 Powder Metallurgy World Congress, Seite 1244 bis 1247 (Japan Society of Powder and Powder Metallurgy) beschrieben.The injection molding granulate is produced by mixing, for example kneading, a hard material phase and a metal component with an organic binder. The metal component regularly consists of a so-called binding metal, which leads to better adhesion of the particles of the hard material phase to one another. The metallic component and the hard phase have hitherto had to be mixed with one another before being mixed with the organic binder, in order later to obtain a homogeneous particle distribution in the granulate and, for example, to prevent the formation of "binder lakes". This premixing is usually carried out by Grinding, for example in ball mills, usually using a solvent such as alcohol. The need for premixing is described, for example, in EP-B 0 443 048 and EP-B 0 516 165. The heat generated during grinding results in the softer components being forged onto the harder components. This leads to a particularly permanent homogeneous mixture of the components. This forging effect is described, for example, by DR Moyle, Proceedings of 1993 Powder Metallurgy World Congress, pages 1244 to 1247 (Japan Society of Powder and Powder Metallurgy).

Nachteil der bisherigen Verfahren ist ihr erheblicher Aufwand für die Herstellung eines möglichst homogenen Spritzguß-Granulats, vor allem die notwendige Vorvermischung der Komponenten, die etwa in einer Mühle bis zu 48 Stunden dauern kann.The disadvantage of the previous processes is their considerable effort for the production of the most homogeneous possible injection molding granulate, above all the necessary premixing of the components, which can take up to 48 hours in a mill.

Aufgabe der vorliegenden Erfindung war deshalb die Bereitstellung eines Verfahrens zur Herstellung eines Spritzguß-Granulats, das technisch weniger aufwendig ist, aber zu vergleichbar guten Ergebnissen führt. Dabei sollten die Homogenität des Granulats und die sich daraus ergebenden vorteilhaften Materialeigenschaften des Formteils möglichst erhalten bleiben.The object of the present invention was therefore to provide a method for producing an injection molding granulate which is less technically complex, but which leads to comparably good results. The homogeneity of the granules and the resulting advantageous material properties of the molded part should be preserved as far as possible.

Diese Aufgabe wird durch das nachstehende Verfahren zur Herstellung von Granulat gelöst. Dabei wird mindestens eine Hartstoffphase mit einem Metallpulver und einem Bindemittel vermischt und granuliert, wobei keine Vormischung der Hartstoffphase und des Metallpulvers vor der Vermischung mit dem Bindemittel stattfindet und das Bindemittel eine Viskosität von 20 bis 200, vorzugsweise von 30 bis 100 cm3/10 min nach DIN 53735 bei 195 °C und 2,16 kg Belastungsgewicht aufweist. In der Regel ist das Metallpulver ein sog. Bindemetallpulver, das die Haftung der Partikel aneinander verbessert. Sowohl die Hartstoffphase, wie auch die Metallphase können auch aus mehreren verschiedenen Materialien bestehen. Neben der Hartstoffphase, der Metallkomponente und dem Bindemittel kann das Granulat auch organische Additive zur Dispergierung und Oberflächenmodifikation enthalten. Außerdem können dem Granulat auch Netzmittel, Plastifiziermittel oder andere Hilfsmittel, die die rheologischen Eigenschaften der Granulate bei der Verformung beeinflussen, beigemengt werden.This object is achieved by the process below for the production of granules. In this case, at least one hard material phase is mixed with a metal powder and a binder and granulated with no premixing of the hard phase and the metal powder before mixing takes place with the binder and the binder has a viscosity of 20 to 200, preferably from 30 to 100 cm 3/10 min according to DIN 53735 at 195 ° C and 2.16 kg load weight. As a rule, the metal powder is a so-called binder metal powder, which improves the adhesion of the particles to one another. Both the hard material phase and the metal phase can also consist of several different materials. In addition to the hard material phase, the metal component and the binder, the granules can also contain organic additives for dispersion and surface modification. In addition, wetting agents, plasticizers or other auxiliaries which influence the rheological properties of the granules during shaping can also be added to the granules.

Durch die Verwendung von Bindemitteln mit der angegebenen Viskosität kann der Vorvermischungsschritt der Metallkomponente und der Hartstoffphase wider Erwarten entfallen. Das wird darauf zurückgeführt, daß die Vermischung dieser Komponenten mit dem hochviskosen organischen Bindemittel zu hohen Scherkräften in der Mischung führt, so daß Agglomerate von Partikeln der Hartstoffphase oder der Metallkomponente aufgelöst werden oder nicht entstehen können. Damit wird eine sehr homogene Verteilung der Komponenten in dem Granulat erreicht, die sich in entsprechenden Eigenschaffen des fertigen Formteils niederschlagen. Durch die Anwendung des erfindungsgemäßen Verfahrens werden auch die Fließeigenschaften des Granulats beim Spritzguß verbessert, wodurch die Formung komplexer Teile erheblich erleichtert wird. Schließlich werden auch die Entbinderungszeiten deutlich verkürzt.By using binders with the specified viscosity, the premixing step of the metal component and the hard material phase can, contrary to expectations, be omitted. This is attributed to the fact that the mixing of these components with the highly viscous organic binder leads to high shear forces in the mixture, so that agglomerates of particles of the hard material phase or the metal component can be dissolved or not be formed. This results in a very homogeneous distribution of the components in the granulate, which are reflected in the corresponding properties of the finished molded part. By using the method according to the invention, the flow properties of the granules during injection molding are also improved, as a result of which the shaping of complex parts is made considerably easier. Finally, the delivery time is significantly reduced.

Die Mischung der Metallkomponente und der Hartstoffphase mit dem Bindemittel kann grundsätzlich nach allen bekannten einschlägigen Verfahren erfolgen. Typischerweise extrudiert oder knetet man die Komponenten bei Temperaturen von 150 bis 200 °C, kühlt sie dann ab und granuliert sie.The mixing of the metal component and the hard material phase with the binder can in principle be carried out by all known relevant processes. Typically, the components are extruded or kneaded at temperatures of 150 to 200 ° C., then cooled and granulated.

Bindemittel, die den Entfall des Vorvermischungsschritts zulassen, sind vor allem hochviskose Bindemittel, die zu mindestens 70 Gew.-% aus mindestens einem Polyacetal, insbesondere aus mindestens einem Polyoxymethylen oder einem Polyoxymethylenhomo- oder -copolymerisat enthalten, insbesondere daraus bestehen. Vorzugsweise beträgt die Viskosität dieser ersten Komponente des Bindemittels von 25 bis 50 cm3/10 min nach DIN 53735 bei 195 °C und 2,16 kg Belastungsgewicht, so daß sich die angegebene Gesamtviskosität des Bindemittels ergibt. Als zweite Komponente des Bindemittels können bis zu 30 Gew.-% weitere Polymere verwendet werden, vorzugsweise Polybutandiolformal, Polyethylen oder Polypropylen oder eine Mischung aus mindestens zwei dieser Polymere. Polybutandiolformal weist dabei vorzugsweise eine relative Molmasse von 6.000 bis 80.000 auf. Polyacetalbindemittel, die bei geeigneter Viskosität im Rahmen der Erfindung Verwendung finden können, wurden auch in EP 413 231, EP 444 475, EP 446 708 und EP 465 940 beschrieben. Der Volumenanteil des Bindemittels an dem Granulat beträgt vorzugsweise 30 bis 70%.Binders which allow the premixing step to be dispensed with are, in particular, highly viscous binders which contain at least 70% by weight of at least one polyacetal, in particular of at least one polyoxymethylene or a polyoxymethylene homo- or copolymer consist of it. Preferably the viscosity is the first component of the binder of 25 to 50 cm 3/10 min according to DIN 53735 at 195 ° C and 2.16 kg load weight, thus resulting in the specified overall viscosity of the binder. Up to 30% by weight of further polymers can be used as the second component of the binder, preferably polybutanediol formal, polyethylene or polypropylene or a mixture of at least two of these polymers. Polybutanediol formal preferably has a relative molar mass of 6,000 to 80,000. Polyacetal binders which can be used with a suitable viscosity in the context of the invention have also been described in EP 413 231, EP 444 475, EP 446 708 and EP 465 940. The volume fraction of the binder in the granules is preferably 30 to 70%.

Bevorzugt ist ein Verfahren, bei dem als Hartstoffphase ein Pulver aus mindestens einem Carbid, Nitrid oder Carbonitrid von Bor oder einem Übergangsmetall, insbesondere einem Element der Gruppe IVa, Va oder VIa des Periodensystems verwendet wird. Als Metallpulver wird vorzugsweise mindestens ein Element- oder Legierungspulver eines Elements der Gruppe Fe, Co, Ni, Cr, Mo, W, vorzugsweise Co, Ni oder Cr verwendet.A method is preferred in which a powder of at least one carbide, nitride or carbonitride of boron or a transition metal, in particular an element of group IVa, Va or VIa of the periodic table, is used as the hard material phase. At least one element or alloy powder of an element from the group Fe, Co, Ni, Cr, Mo, W, preferably Co, Ni or Cr is preferably used as the metal powder.

Vorzugsweise besitzt entweder das Metallpulver oder die Hartstoffphase oder beide Pulver eine mittlere Korngröße von weniger als 40µm, vorzugsweise von weniger als 20 µm.Either the metal powder or the hard material phase or both powders preferably have an average grain size of less than 40 μm, preferably less than 20 μm.

Erfindungsgemäß wird auch ein Verfahren zur Herstellung von Formteilen durch Spritzgießen bereitgestellt, bei dem ein Granulat, das mit Hilfe eines der obigen Verfahren hergestellt wurde, geformt, entbindert und versintert wird. Die Formung der Spritzgußteile kann dadurch erfolgen, daß das Granulat mit Hilfe üblicher Schnecken- oder Kolbenspritzgußmaschinen in Formen geleitet und bei Temperaturen von typischerweise 170 bis 200 °C und bei Drücken zwischen 200 und 2000 bar verformt wird. Die Entfernung des Bindemittels aus dem geformten Grünling erfolgt vorzugsweise in einer Atmosphäre, die Säure, insbesondere Oxalsäure, oder Bortrifluorid enthält. Dies gilt vor allem für Polyacetalbinder der oben beschriebenen Art. Für andere Bindemittel sind andere Entbinderungsbedingungen unter Umständen günstiger. Die Versinterung schließlich erfolgt vorzugsweise in Inertgasatmosphäre, in reduzierender Atmosphäre oder im Vakuum. In geeigneten Fällen kann auch unter erhöhtem Inertgasdruck gesintert werden. Dabei müssen die Sinterbedingungen auf den jeweiligen Einzelfall abgestimmt werden, denn diese sind für die korrekte Einstellung des Kohlenstoffgehalts in dem Formteil von großer Bedeutung. Der Kohlenstoffgehalt wiederum ist von entscheidender Bedeutung für die erhaltenen Materialeigenschaften.According to the invention there is also provided a method for producing molded parts by injection molding, in which a granulate which has been produced using one of the above methods is shaped, debindered and sintered. The injection molded parts can be shaped by guiding the granules into molds using conventional screw or piston injection molding machines and at temperatures of typically 170 to 200.degree and is deformed at pressures between 200 and 2000 bar. The binder is preferably removed from the shaped green body in an atmosphere which contains acid, in particular oxalic acid, or boron trifluoride. This applies above all to polyacetal binders of the type described above. For other binders, other debinding conditions may be more favorable. Finally, the sintering is preferably carried out in an inert gas atmosphere, in a reducing atmosphere or in a vacuum. In suitable cases, sintering can also be carried out under increased inert gas pressure. The sintering conditions must be tailored to the individual case, because these are of great importance for the correct setting of the carbon content in the molded part. The carbon content in turn is of crucial importance for the material properties obtained.

Erfindungsgemäßes BeispielExample according to the invention

In einem Beispiel nach vorliegender Erfindung wurde eine Mischung folgender Komponenten in einen beheizbaren Kneter vorgelegt: 8800 g pulverförmiges WC, das mit 0,1 Gew.-% NbC gedopt war und eine mittlere Teilchengröße von 2,2 µm aufwies; 1200 g pulverförmiges Co mit einer mittleren Teilchengröße von 1,6 µm; 40 g Polyethylenglykol mit einem mittleren Molgewicht von etwa 800; 35 g Polybutandiolformal mit einem mittleren Molgewicht von etwa 30000; 850 g Polyoxymethylen mit einem Anteil von 2 Gew.-% Butandiolformal. Diese Mischung wurde bei 175 °C aufgeschmolzen und für eine Stunde homogenisiert. Anschließend wurde abgekühlt und granuliert. Das Granulat wies einen Melt Flow Index nach DIN 53735, gemessen bei 190 °C und 10 kg Belastungsgewicht, von 27 cm3 /10 min auf.In an example according to the present invention, a mixture of the following components was placed in a heatable kneader: 8,800 g of powdery WC which was doped with 0.1% by weight of NbC and had an average particle size of 2.2 μm; 1200 g of powdered Co with an average particle size of 1.6 microns; 40 g of polyethylene glycol with an average molecular weight of about 800; 35 g of polybutanediol formal with an average molecular weight of about 30,000; 850 g of polyoxymethylene with a proportion of 2% by weight of butanediol formal. This mixture was melted at 175 ° C. and homogenized for one hour. It was then cooled and granulated. The granules had a Melt Flow Index according to DIN 53735, measured at 190 ° C and load of 10 kg weight, of 27 cm 3/10 min.

Das Granulat wurde zu Formteilen spritzgegossen, die anschließend in einer Oxalsäure/Stickstoff-Gasatmosphäre bei 140 °C entbindert wurden. Die Entbinderungsgeschwindigkeit lag bei 1 mm/h, d.h. mit jeder Stunde des Entbinderungsvorgangs wurde der Formteilgrünling rundum in einer Tiefe von 1 mm bindemittelfrei. Nach dem Sintern in Inertgasatmosphäre bei 1450 °C erhielt man Formteile mit einer Dichte von 14,3 g/ml und homogener Mikrostruktur. Es traten keine "Bindemittelseen" und kein Agglomerate von WC-Teilchen auf. Die Dreipunkt-Biegefestigkeit nach DIN-ISO 3327 lag an Proben "as fired" bei 2200 MPa.The granules were injection molded into moldings, which were then debindered in an oxalic acid / nitrogen gas atmosphere at 140 ° C. The rate of debinding was 1 mm / h, i.e. with each hour of the debinding process, the molded green part became free of binder all around at a depth of 1 mm. After sintering in an inert gas atmosphere at 1450 ° C., molded parts with a density of 14.3 g / ml and a homogeneous microstructure were obtained. There were no "binder lakes" and no agglomerates of WC particles. The three-point bending strength according to DIN ISO 3327 was 2200 MPa on samples "as fired".

Vergleichsbeispiel 1Comparative Example 1

In dem Vergleichsbeispiel wurde eine Mischung folgender Komponenten in eine beheizbaren Kneter vorgelegt: 8800 g pulverförmiges WC, das mit 0,1 Gew.-% NbC gedopt war, und eine mittlere Teilchengröße von 2,2 µm aufwies, und 1200 g pulverförmiges Co mit einer mittleren Teilchengröße von 1,6 µm; als Bindemittel wurden 600 g Montanesterwachs, das derart niederviskos war, daß eine Messung des Melt Flow Index nicht möglich war, und 60 g Polyethylen mit geringer Dichte (LDPE) zugegeben. Diese Mischung wurde bei 120 °C aufgeschmolzen und für eine Stunde homogenisiert. Anschließend wurde abgekühlt und granuliert. Das Granulat wies einen Melt Flow Index nach DIN 53735, gemessen bei 140 °C und 2,16 kg Belastungsgewicht, von 21 cm3/10 min auf.In the comparative example, a mixture of the following components was placed in a heatable kneader: 8,800 g of powdery WC, which was doped with 0.1% by weight of NbC and had an average particle size of 2.2 μm, and 1200 g of powdery Co with a average particle size of 1.6 µm; 600 g of montan ester wax, which was so low-viscosity that it was not possible to measure the melt flow index, and 60 g of low-density polyethylene (LDPE) were added as binders. This mixture was melted at 120 ° C. and homogenized for one hour. It was then cooled and granulated. The granules had a Melt Flow Index according to DIN 53735, measured at 140 ° C and 2.16 kg load weight, of 21 cm 3/10 min.

Dieses Granulat wurde zu Formteilen spritzgegossen. Das anschließende Entbindern wurde wie folgt durchgeführt: Aufheizen des Formteils in zwei Schritten, zunächst auf 350 °C mit einer Rate von 10 K/h in Stickstoffatmosphäre, dann weiter auf 650 °C mit einer Rate von 50 K/h in Vakuum (höchstens 0,7 mbar); Halten der erreichten Temperatur für 1 Stunde; Abkühlen. Anschließend wurden die entbinderten Formteile in Inertgasatmosphäre bei 1450 °C gesintert. Dadurch wurden Formteile mit einer Dichte von 13,9 g/ml erhalten. Die Mikrostruktur war nicht hinreichend homogen, es waren "Bindemittelseen" und Poren in Mikrostrukturaufnahmen sichtbar. Die Dreipunkt-Biegefestigkeit nach DIN-ISO 3327 betrug bei den Proben "as fired" 1530 MPa.This granulate was injection molded into molded parts. The subsequent debinding was carried out as follows: heating the molded part in two steps, first to 350 ° C. at a rate of 10 K / h in a nitrogen atmosphere, then further to 650 ° C. at a rate of 50 K / h in vacuum (at most 0 , 7 mbar); Maintaining the temperature reached for 1 hour; Cooling down. The debindered moldings were then sintered in an inert gas atmosphere at 1450 ° C. This gave moldings with a density of 13.9 g / ml. The microstructure was not sufficiently homogeneous, "binding lakes" and pores were visible in microstructure images. The three-point bending strength according to DIN-ISO 3327 was 1530 MPa for the samples "as fired".

Vergleichsbeispiel 2Comparative Example 2

In einem Vergleichsbeispiel wurde zunächst eine Mischung aus 88 Gew.-% WC-Pulver und 12 Gew.-% Co-Pulver in Alkohol in einer Kugelmühle für 48 Stunden naß gemahlen. Das Pulvergemisch wurde anschließend getrocknet und wie in obigem erfindungsgemäßen Beispiel zusammen mit den anderen dort angegebenen Komponenten zu einem Granulat verarbeitet. Der Melt Flow Index des Granulats betrug 16 cm3/10 min, gemessen nach DIN 53735 bei 190 °C und 21,6 kg Belastungsgewicht.In a comparative example, a mixture of 88% by weight WC powder and 12% by weight co-powder in alcohol was first wet-milled in a ball mill for 48 hours. The powder mixture was then dried and, as in the example according to the invention above, processed together with the other components specified therein to give a granulate. The Melt Flow Index of the granules was 16 cm 3/10 min, measured according to DIN 53735 at 190 ° C and 21.6 kg load weight.

Das Granulat wurde wie in dem erfindungsgemäßen Beispiel spritzgegossen. Die erhaltenen Formteilgrünlinge wurden unter identischen Bedingungen wie oben entbindert, wobei die Geschwindigkeit nur 0,5 mm/h betrug. Nach dem Sintern wurden Formteile erhalten, deren Gefüge und Eigenschaften den mit dem erfindungsgemäßen Verfahren nach obigem Beispiel hergestellten Teilen weitgehend identisch waren.The granules were injection molded as in the example according to the invention. The molded green parts obtained were debindered under identical conditions as above, the speed being only 0.5 mm / h. After sintering, molded parts were obtained whose structure and properties were largely identical to the parts produced by the process according to the invention according to the example above.

Vergleichsbeispiel 2 zeigt, daß man mit dem erfindungsgemäßen Verfahren unter Verzicht auf eine Vorvermischung homogene Formteile herstellen kann, die außerdem leichter zu entbindern sind und gute Festigkeit aufweisen. Vorteilhaft ist dabei auch, daß das nach dem erfindungsgemäßen Verfahren hergestellte Granulat fließfähiger ist, was die Formung komplexer Teile erleichtert. Vergleichsbeispiel 1 zeigt dagegen, daß die Vorvermischung bei bisher üblichen Bindern nur unter erheblichen Einbußen in der Homogenität und Festigkeit der Formteile weggelassen werden kann.Comparative example 2 shows that the process according to the invention can be used to produce homogeneous molded parts which do not require premixing, which are also easier to debinding and have good strength. It is also advantageous that the granulate produced by the process according to the invention is more flowable, which is the formation of complex parts facilitated. Comparative example 1, on the other hand, shows that the premixing in binders customary hitherto can only be omitted with considerable losses in the homogeneity and strength of the molded parts.

Claims (9)

Verfahren zur Herstellung von Granulat, bei dem mindestens eine Hartstoffphase mit einem Metallpulver und einem Bindemittel vermischt und granuliert wird, dadurch gekennzeichnet, daß keine Vormischung der Hartstoffphase mit dem Metallpulver vor der Vermischung mit dem Bindemittel stattfindet und das Bindemittel eine Viskosität von 20 bis 200, vorzugsweise von 30 bis 100 cm3/10 min nach DIN 53735 bei 195 °C und 2,16 kg Belastungsgewicht aufweist.Process for the production of granules, in which at least one hard material phase is mixed and granulated with a metal powder and a binder, characterized in that there is no premixing of the hard material phase with the metal powder before mixing with the binder and the binder has a viscosity of 20 to 200, preferably from 30 to 100 cm 3/10 min according to DIN 53735 at 195 ° C and 2.16 kg load weight. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß das Bindemittel aus a) 70 bis 100 Gew.-% aus mindestens einem Polyacetal, insbesondere aus mindestens einem Polyoxymethylen oder Polyoxymethylenhomo- oder -copolymerisat, wobei diese Komponente vorzugsweise eine Viskosität von 25 bis 50 cm3/10 min nach DIN 53735 bei 195 °C und 2,16 kg Belastungsgewicht aufweist, und b) 0 bis 30 Gew.-% weiterer Polymere, insbesondere Polybutandiolformal, vorzugsweise mit einer relativen Molmasse von 6.000 bis 80.000, Polyethylen oder Polypropylen oder einer Mischung daraus. besteht.A method according to claim 1, characterized in that the binder from a) 70 to 100 wt .-% of at least one polyacetal, in particular of at least one polyoxymethylene or polyoxymethylene homopolymer or copolymer, said component preferably has a viscosity of 25 to 50 cm 3/10 min according to DIN 53735 at 195 ° C and 2 , 16 kg load weight, and b) 0 to 30% by weight of further polymers, in particular polybutanediol formal, preferably with a relative molecular weight of 6,000 to 80,000, polyethylene or polypropylene or a mixture thereof. consists. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß der Volumeranteil des Bindemittels an dem Granulat 30 bis 70% beträgt.Method according to one of the preceding claims, characterized in that the volume fraction of the binder in the granulate is 30 to 70%. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß als Hartstoffphase ein Pulver aus mindestens einem Carbid, Nitrid oder Carbonitrid von Bor oder einem Übergangsmetall, insbesondere einem Element der Gruppe IVa, Va oder VIa des Periodensystems verwendet wird.Method according to one of the preceding claims, characterized in that a powder of at least one carbide, nitride or carbonitride of boron or a transition metal, in particular an element from group IVa, Va or VIa of the periodic table, is used as the hard material phase. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß als Metallpulver mindestens ein Element- oder Legierungspulver eines Elements der Gruppe Fe, Co, Ni, Cr, Mo, W, vorzugsweise Co, Ni oder Cr verwendet wird.Method according to one of the preceding claims, characterized in that at least one element or alloy powder of an element from the group Fe, Co, Ni, Cr, Mo, W, preferably Co, Ni or Cr is used as the metal powder. Verfahren nach einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, daß die Harrtstoffphase und/oder das Metallpulver eine mittlere Korngröße von weniger als 40µm, vorzugsweise von weniger als 20 µm aufweist.Method according to one of the preceding claims, characterized in that the hard material phase and / or the metal powder has an average grain size of less than 40 µm, preferably less than 20 µm. Verfahren zur Herstellung von Formteilen durch Spritzgießen, bei dem ein Granulat, das mit Hilfe eines Verfahrens nach einem der vorhergehenden Ansprüche hergestellt wurde, geformt, entbindert und versintert wird.Process for the production of molded parts by injection molding, in which a granulate which has been produced with the aid of a process according to one of the preceding claims is shaped, debindered and sintered. Verfahren nach Anspruch 7, dadurch gekennzeichnet, daß die Entfernung des Bindemittels in einer Atmosphäre vorgenommen wird, die Säure, insbesondere Oxalsäure, oder Bortrifluorid enthält.A method according to claim 7, characterized in that the removal of the binder is carried out in an atmosphere which contains acid, especially oxalic acid, or boron trifluoride. Verfahren nach einem der Ansprüche 7 oder 8, dadurch gekennzeichnet, daß die Versinterung in Inertgasatmosphäre, in reduzierender Atmosphäre oder im Vakuum erfolgt.Method according to one of claims 7 or 8, characterized in that the sintering takes place in an inert gas atmosphere, in a reducing atmosphere or in a vacuum.
EP97105701A 1996-04-09 1997-04-07 Process for preparing granulate and articles from hard metal or cermet material Withdrawn EP0800882A3 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19614006 1996-04-09
DE19614006A DE19614006A1 (en) 1996-04-09 1996-04-09 Process for the production of granules and molded parts from hard metal or cermet materials

Publications (2)

Publication Number Publication Date
EP0800882A2 true EP0800882A2 (en) 1997-10-15
EP0800882A3 EP0800882A3 (en) 1999-02-03

Family

ID=7790799

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97105701A Withdrawn EP0800882A3 (en) 1996-04-09 1997-04-07 Process for preparing granulate and articles from hard metal or cermet material

Country Status (7)

Country Link
US (1) US5860055A (en)
EP (1) EP0800882A3 (en)
JP (1) JPH1036901A (en)
KR (1) KR970069940A (en)
CN (1) CN1083016C (en)
DE (1) DE19614006A1 (en)
TW (1) TW397726B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2496605C1 (en) * 2012-05-10 2013-10-27 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" Method of plasticiser feed and device to this end

Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2955754B1 (en) * 1998-06-01 1999-10-04 有限会社モールドリサーチ Composition for injection molding of metal powder and injection molding and sintering method using the composition
DE19855422A1 (en) 1998-12-01 2000-06-08 Basf Ag Hard material sintered part with a nickel- and cobalt-free, nitrogen-containing steel as a binder of the hard material phase
CH694401A5 (en) 1999-05-26 2004-12-31 Basf Ag Low-nickel, low-molybdenum, biocompatible, non-allergenic, corrosion-resistant austenitic steel.
CN1495281A (en) 1999-06-24 2004-05-12 Basf Application of low-nickel austenite steel
US6355207B1 (en) * 2000-05-25 2002-03-12 Windfall Products Enhanced flow in agglomerated and bound materials and process therefor
US7326274B2 (en) * 2001-10-18 2008-02-05 Praxis Powder Technology, Inc. Binder compositions and methods for binder assisted forming
DE10244486A1 (en) * 2002-09-24 2004-04-01 Gkn Sinter Metals Gmbh Mixture for the production of sintered molded parts
KR20080027171A (en) * 2006-09-22 2008-03-26 세이코 엡슨 가부시키가이샤 Manufacturing method and sintered body
CN101764603B (en) * 2009-10-15 2015-01-28 常蔚科技(深圳)有限公司 Sensor shell and manufacturing method thereof
CN101764602B (en) * 2009-10-15 2015-07-01 常蔚科技(深圳)有限公司 Sensor shell and manufacturing method thereof
CN101764601B (en) * 2009-10-15 2015-09-30 常蔚科技(深圳)有限公司 A kind of sensor outer housing and manufacture method thereof
CN101764600B (en) * 2009-10-15 2015-04-29 常蔚科技(深圳)有限公司 Sensor shell and manufacturing method thereof
CN101764599B (en) * 2009-10-15 2015-04-29 常蔚科技(深圳)有限公司 Sensor shell and manufacturing method thereof
JP5830808B2 (en) 2010-03-24 2015-12-09 株式会社ニチリン Vulcanized adhesive laminate of fluororubber and synthetic rubber
EP3019648B1 (en) 2013-07-11 2021-02-17 Tundra Composites, LLC Composite filament comprising surface modified particulate, and sintered extruded products
CN106624634B (en) * 2016-12-07 2018-11-02 杭州正驰达精密机械有限公司 A kind of production method of high-specific gravity tungsten alloy autoplugger
EP4036167A1 (en) * 2019-12-24 2022-08-03 Kolon Plastics, Inc. Binder composition for metal powder injection molding

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4397889A (en) * 1982-04-05 1983-08-09 Gte Products Corporation Process for producing refractory powder
EP0114746A2 (en) * 1983-01-21 1984-08-01 Celanese Corporation Polyacetal binders for injection moulding of ceramics
US4624812A (en) * 1983-01-21 1986-11-25 Celanese Corporation Injection moldable ceramic composition containing a polyacetal binder and process of molding
EP0329475A2 (en) * 1988-02-18 1989-08-23 Sanyo Chemical Industries Ltd. Mouldable composition
EP0413231A2 (en) * 1989-08-16 1991-02-20 BASF Aktiengesellschaft Process for the production of an inorganic sintered body
EP0424739A2 (en) * 1989-10-24 1991-05-02 BASF Aktiengesellschaft Process for producing preforms from ceramic or metallic fibers
EP0444475A2 (en) * 1990-02-21 1991-09-04 BASF Aktiengesellschaft Thermoplastic composition for the preparation of ceramic moulding masses
EP0446708A2 (en) * 1990-03-08 1991-09-18 BASF Aktiengesellschaft Thermoplastic materials for manufacturing metallic articles
EP0465940A2 (en) * 1990-07-07 1992-01-15 BASF Aktiengesellschaft Thermoplastic masses for preparing metallic mouldings
US5279640A (en) * 1992-09-22 1994-01-18 Kawasaki Steel Corporation Method of making iron-based powder mixture

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5603071A (en) * 1989-09-14 1997-02-11 Sumitomo Electric Industries, Ltd. Method of preparing cemented carbide or cermet alloy
US5665289A (en) * 1990-05-07 1997-09-09 Chang I. Chung Solid polymer solution binders for shaping of finely-divided inert particles
TW362999B (en) * 1992-06-02 1999-07-01 Advanced Materials Technplogies Pte Ltd Injection-mouldable metal powder-binder feedstock and method of forming metal injection-moulded article
US5332543A (en) * 1992-08-26 1994-07-26 Advanced Materials Technologies Pte Ltd Method for producing articles from particulate materials using a binder derived from an idealized TGA curve
EP0645804B1 (en) * 1993-09-16 2003-04-23 Sumitomo Electric Industries, Limited Metal casing for semiconductor device having high thermal conductivity and thermal expansion coefficient similar to that of semiconductor and method for manufacturing the same
JPH07173503A (en) * 1993-11-04 1995-07-11 Kobe Steel Ltd Binder for powder metallurgy and powdery mixture for powder metallurgy
DE4408304A1 (en) * 1994-03-11 1995-09-14 Basf Ag Sintered parts made of oxygen-sensitive, irreducible powders and their production by injection molding
US5641920A (en) * 1995-09-07 1997-06-24 Thermat Precision Technology, Inc. Powder and binder systems for use in powder molding
US5678165A (en) * 1995-12-06 1997-10-14 Corning Incorporated Plastic formable mixtures and method of use therefor

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4397889A (en) * 1982-04-05 1983-08-09 Gte Products Corporation Process for producing refractory powder
EP0114746A2 (en) * 1983-01-21 1984-08-01 Celanese Corporation Polyacetal binders for injection moulding of ceramics
US4624812A (en) * 1983-01-21 1986-11-25 Celanese Corporation Injection moldable ceramic composition containing a polyacetal binder and process of molding
EP0329475A2 (en) * 1988-02-18 1989-08-23 Sanyo Chemical Industries Ltd. Mouldable composition
EP0413231A2 (en) * 1989-08-16 1991-02-20 BASF Aktiengesellschaft Process for the production of an inorganic sintered body
EP0424739A2 (en) * 1989-10-24 1991-05-02 BASF Aktiengesellschaft Process for producing preforms from ceramic or metallic fibers
EP0444475A2 (en) * 1990-02-21 1991-09-04 BASF Aktiengesellschaft Thermoplastic composition for the preparation of ceramic moulding masses
EP0446708A2 (en) * 1990-03-08 1991-09-18 BASF Aktiengesellschaft Thermoplastic materials for manufacturing metallic articles
EP0465940A2 (en) * 1990-07-07 1992-01-15 BASF Aktiengesellschaft Thermoplastic masses for preparing metallic mouldings
US5279640A (en) * 1992-09-22 1994-01-18 Kawasaki Steel Corporation Method of making iron-based powder mixture

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2496605C1 (en) * 2012-05-10 2013-10-27 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" Method of plasticiser feed and device to this end

Also Published As

Publication number Publication date
CN1083016C (en) 2002-04-17
US5860055A (en) 1999-01-12
KR970069940A (en) 1997-11-07
CN1167836A (en) 1997-12-17
DE19614006A1 (en) 1997-10-16
TW397726B (en) 2000-07-11
EP0800882A3 (en) 1999-02-03
JPH1036901A (en) 1998-02-10

Similar Documents

Publication Publication Date Title
EP2043802B1 (en) Thermoplastic masses containing binding agents for the production of metallic molds
EP0800882A2 (en) Process for preparing granulate and articles from hard metal or cermet material
EP0446708B1 (en) Thermoplastic materials for manufacturing metallic articles
EP0444475B1 (en) Thermoplastic composition for the preparation of ceramic moulding masses
DE3740547C2 (en) Process for the manufacture of extruder screws and extruder screws made therewith
DE3881011T2 (en) STARTING MATERIAL FOR THE SLICK ENERGY METHOD FOR METAL POWDER AND METHOD FOR THE PRODUCTION OF SINTERED MOLDED BODIES.
DE3205877C2 (en)
DE3881283T2 (en) Metal binder and composition for molding.
DE68916778T2 (en) Method for debinding injection molded objects.
DE4021739A1 (en) THERMOPLASTIC MEASURES FOR THE PRODUCTION OF METALLIC MOLDED BODIES
DE19925197A1 (en) Organic binder for injection moulding for manufacture of metal powder compact
WO2001081467A1 (en) Binding agent for inorganic material powders for producing metallic and ceramic moulded bodies
DE3942745A1 (en) CERAMIC INJECTION MOLDING MATERIAL AND INJECTION MOLDING METHOD USED THEREOF
EP2321076B1 (en) Binder for the production of sintered molded articles
EP2183067B1 (en) Molding compound and method for producing a molding compound
DE69023062T2 (en) Connection to injection molding.
EP0217807B1 (en) Sintering method
EP0710516A2 (en) Process and injection-moulding compound for the manufacturing of shaped metallic bodies
DE102008062155B4 (en) A method for producing a solidified, ready-to-use ceramic sintered body, sintered body and use of a ceramic mass
DE4120687C1 (en) Porous, sintered parts prepn., used e.g. as filters, catalyst carriers - comprises mixing metal or ceramic powder with organic binder or plasticiser contg. polymer of vinyl] aromatic cpd.
EP0256449B1 (en) Powder-metallurgical manufacture of work pieces from a heat-resisting aluminium alloy
EP0951460B1 (en) Moulding compounds and method of producing ceramic moulded bodies with a metallic appearance
DE3884300T2 (en) Magnetic polymer compositions.
DE3043321A1 (en) SINTER PRODUCT FROM METAL ALLOY AND THE PRODUCTION THEREOF
DE1810453A1 (en) Arc Resistant Polyoxymethylene Polymers

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE CH DE ES FR GB IT LI NL SE

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): AT BE CH DE ES FR GB IT LI NL SE

17P Request for examination filed

Effective date: 19990301

17Q First examination report despatched

Effective date: 20001207

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Withdrawal date: 20010508