EP0368082A2 - Oxygenated molybdenum metal powder and process for its preparation - Google Patents

Oxygenated molybdenum metal powder and process for its preparation Download PDF

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Publication number
EP0368082A2
EP0368082A2 EP89119866A EP89119866A EP0368082A2 EP 0368082 A2 EP0368082 A2 EP 0368082A2 EP 89119866 A EP89119866 A EP 89119866A EP 89119866 A EP89119866 A EP 89119866A EP 0368082 A2 EP0368082 A2 EP 0368082A2
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EP
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Prior art keywords
metal powder
molybdenum metal
molybdenum
oxygen
carbon dioxide
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EP89119866A
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German (de)
French (fr)
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EP0368082B1 (en
EP0368082A3 (en
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Theodor Alexander Dr. Weber
Wolfgang Kummer
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HC Starck GmbH
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HC Starck GmbH
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    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
    • C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
    • C23C4/06—Metallic 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
    • B22F1/14—Treatment of metallic powder
    • B22F1/145—Chemical treatment, e.g. passivation or decarburisation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/12—All metal or with adjacent metals
    • Y10T428/12181—Composite powder [e.g., coated, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991—Coated
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2982—Particulate matter [e.g., sphere, flake, etc.]
    • Y10T428/2991—Coated
    • Y10T428/2993—Silicic or refractory material containing [e.g., tungsten oxide, glass, cement, etc.]

Definitions

  • the present invention relates to molybdenum metal powder with a shell made of oxides of molybdenum and methods for its production.
  • Molybdenum metal powders with a defined oxygen content are used in plasma spraying in order to achieve particularly hard spray layers. Flame spraying with an ethyne / oxygen mixture is preferably carried out using molybdenum wire as the melting material. The metal droplets are partially oxidized during flame spraying. (Gmelin Handbook of Inorganic Chemistry, Molybdenum, Supplement Volume A1, 1977, pages 182ff.)
  • a method for producing oxygen-containing molybdenum powder by an oxidizing plasma treatment is known from US Pat. No. 4,146,388.
  • EP-A 233 574 describes three processes for producing oxygen-containing molybdenum wettable powders. These are the treatment of molybdenum metal with dilute hydrogen peroxide solution, the thermal treatment of molybdenum metal powder with water vapor under an inert gas atmosphere and the production of agglomerated oxygen-containing molybdenum metal powder using molybdenum oxides.
  • a disadvantage of the molybdenum powders thus produced is that their oxygen content is not precisely defined.
  • these molybdenum metal powders are often inhomogeneous.
  • these molybdenum metal powders often have a MoO3 content, which has a disadvantageous effect on the spray behavior of the powder.
  • the object of the present compound is to provide a molybdenum metal powder with a defined oxygen content which does not have the disadvantages described.
  • the molybdenum metal powder according to the invention has an oxygen content of 1 to 18, preferably 2 to 12% by weight.
  • the oxygen is in a defined form as MoO2 and is in particular on the surface as a homogeneous layer. This oxide layer adheres firmly to the metallic core, so that the molybdenum metal powder according to the invention has very special structural properties.
  • the powder grains consist of a molybdenum metal core and a uniform, closed MoO2 layer.
  • the average diameter of the molybdenum metal powder individual grains is 5 to 90 microns and the thickness of the MoO2 shell 0.1 to 20 microns.
  • the present invention also relates to a method for producing the molybdenum metal powder according to the invention. Surprisingly, this can be carried out in a very easily controllable oxidation of the molybdenum metal powder under a carbon dioxide atmosphere at unexpectedly low temperatures.
  • the subject of this invention is thus a process for the production of molybdenum metal powder with a defined oxygen content, whereby molybdenum metal powder is partially oxidized by thermal treatment in a carbon dioxide atmosphere at temperatures below 1200 ° C.
  • the partial oxidation is preferably carried out at temperatures from 700 to 1200 ° C.
  • the oxygen uptake in the molybdenum metal powder takes place according to the method of the invention exclusively with the formation of MoO2, which can be demonstrated by X-ray diffraction. An equivalent amount of carbon monoxide is released in the reaction.
  • the weight increase in the starting powder is limited to 12% by weight.
  • the increase in the particle diameter of the individual molybdenum metal particles corresponds to the oxygen uptake and the associated change in density.
  • a grain coarsening occurs due to the oxygen absorption of the molybdenum metal powder, the density of the powder decreases.
  • molybdenum metal powders according to the invention were used in spray tests, there was a significant improvement in the hardness properties of the application layers, if instead of known oxide-containing Mo Lybdenum wettable powders or molybdenum spray wire uses the oxygen-doped molybdenum metal powder according to the invention.
  • This invention therefore also relates to the use of the molybdenum metal powder according to one or more of claims 1 to 6 as molybdenum wettable powder.
  • the oxygen content of the metal powder is 3.6% by weight, after 2 hours reaction time 4.6% by weight, after 3 hours reaction time 5.5% by weight.

Abstract

Die vorliegende Erfindung betrifft Molybdänmetallpulver mit einer Hülle aus Oxiden des Molybdäns sowie Verfahren zu dessen Herstellung.The present invention relates to molybdenum metal powder with a shell made of oxides of molybdenum and methods for its production.

Description

Die vorliegende Erfindung betrifft Molybdänmetallpulver mit einer Hülle aus Oxiden des Molybdäns sowie Verfahren zu dessen Herstellung.The present invention relates to molybdenum metal powder with a shell made of oxides of molybdenum and methods for its production.

Molybdänmetallpulver mit einem definierten Sauerstoffge­halt werden beim Plasmaspritzen eingesetzt, um besonders harte Spritzschichten zu erzielen Beim Flammspritzen mit Ethin-Sauerstoffgemisch wird vorzugsweise Molybdän-­Draht als Abschmelzmaterial eingesetzt. Hierbei werden die Metalltröpfchen während des Flammspritzens partiell oxidiert.
(Gmelin Handbuch der anorganischen Chemie, Molybdän, Ergänzungsband Teil A1, 1977, Seiten 182ff.)Molybdenum metal powders with a defined oxygen content are used in plasma spraying in order to achieve particularly hard spray layers. Flame spraying with an ethyne / oxygen mixture is preferably carried out using molybdenum wire as the melting material. The metal droplets are partially oxidized during flame spraying.
(Gmelin Handbook of Inorganic Chemistry, Molybdenum, Supplement Volume A1, 1977, pages 182ff.)

Verfahren zur Herstellung entsprechender sauerstoffhal­tiger Molybdänmetallpulver sind zwar bekannt, jedoch hat sich für Molybdän das Plasmaspritzen gegenüber dem Flammspritzen bisher aus verschiedenen Gründen noch nicht durchsetzen können, da die Bereitstellung ent­sprechender Pulver nicht technisch gewährleistet ist.Processes for producing corresponding oxygen-containing molybdenum metal powders are known, but have For various reasons, plasma spraying has not yet been able to prevail over flame spraying for molybdenum, since the provision of corresponding powders is not technically guaranteed.

Aus der US-A 4.146.388 ist ein Verfahren zur Herstellung sauerstoffhaltiger Molybdänpulver durch eine oxidierende Plasma-Behandlung bekannt. In der EP-A 233 574 werden drei Verfahren zur Herstellung sauerstoffhaltiger Molyb­dän-Spritzpulver beschrieben. Dies sind die Behandlung von Molybdänmetall mit verdünnter Wasserstoffperoxid­lösung, die thermische Behandlung von Molybdänmetallpul­ver mit Wasserdampf unter Inertgasatmosphäre und die Herstellung agglomerierter sauerstoffhaltiger Molybdän­metallpulver unter Verwendung von Molybdänoxiden. Nach­teilig an den so hergestellten Molybdänpulvern ist ihr nicht genau definierter Sauerstoffgehalt. Außerdem sind diese Molybdänmetallpulver häufig inhomogen. Weiterhin weisen diese Molybdänmetallpulver häufig einen MoO₃-­Gehalt auf, der sich nachteilig auf das Spritzverhalten der Pulver auswirkt.A method for producing oxygen-containing molybdenum powder by an oxidizing plasma treatment is known from US Pat. No. 4,146,388. EP-A 233 574 describes three processes for producing oxygen-containing molybdenum wettable powders. These are the treatment of molybdenum metal with dilute hydrogen peroxide solution, the thermal treatment of molybdenum metal powder with water vapor under an inert gas atmosphere and the production of agglomerated oxygen-containing molybdenum metal powder using molybdenum oxides. A disadvantage of the molybdenum powders thus produced is that their oxygen content is not precisely defined. In addition, these molybdenum metal powders are often inhomogeneous. Furthermore, these molybdenum metal powders often have a MoO₃ content, which has a disadvantageous effect on the spray behavior of the powder.

Aufgabe der vorliegenden Verbindung ist es, ein Molyb­dänmetallpulver mit definiertem Sauerstoffgehalt bereit­zustellen, welches die beschriebenen Nachteile nicht aufweist.The object of the present compound is to provide a molybdenum metal powder with a defined oxygen content which does not have the disadvantages described.

Überraschenderweise wurde nun gefunden, daß diese An­forderungen erfüllt werden durch ein Molybdänmetall­ pulver mit einer Hülle aus Oxiden des Molybdäns, wobei die oxidische Hülle aus MoO₂ besteht. In einer bevor­zugten Ausführungsform weist das erfindungsgemäße Molybdänmetallpulver einen Sauerstoffgehalt von 1 bis 18, bevorzugt 2 bis 12 Gew.-%, auf. Der Sauerstoff liegt dabei in definierter Form als MoO₂ vor und befindet sich insbesondere an der Oberfläche als homogene Schicht. Diese Oxidschicht haftet fest am metallischen Kern, so daß das erfindungsgemäße Molybdänmetallpulver ganz be­sondere Struktur-Eigenschaften aufweist.Surprisingly, it has now been found that these requirements are met by a molybdenum metal powder with a shell made of oxides of molybdenum, the oxide shell consisting of MoO₂. In a preferred embodiment, the molybdenum metal powder according to the invention has an oxygen content of 1 to 18, preferably 2 to 12% by weight. The oxygen is in a defined form as MoO₂ and is in particular on the surface as a homogeneous layer. This oxide layer adheres firmly to the metallic core, so that the molybdenum metal powder according to the invention has very special structural properties.

Die Pulverkörner bestehen aus einem Molybdänmetallkern und einer gleichmäßigen, geschlossenen MoO₂-Schicht. Be­vorzugt beträgt der mittlere Durchmesser der Molybdän­metallpulver-Einzelkörner 5 bis 90 µm und die Dicke der MoO₂-Hülle 0,1 bis 20 µm.The powder grains consist of a molybdenum metal core and a uniform, closed MoO₂ layer. Preferably, the average diameter of the molybdenum metal powder individual grains is 5 to 90 microns and the thickness of the MoO₂ shell 0.1 to 20 microns.

Die Oberfläche des erfindungsgemäßen partiell oxidierten Molybdänmetallpulvers zeigt eine typische MoO₂-Färbung. Rasterelektronenmikroskopische (REM)-Aufnahmen zeigen im Gegensatz zur glatten Pulveroberfläche des Ausgangs­materials einen zernarbten, geschlossenen Oxidbelag.The surface of the partially oxidized molybdenum metal powder according to the invention shows a typical MoO₂ color. In contrast to the smooth powder surface of the starting material, scanning electron microscope (SEM) images show a grained, closed oxide coating.

Gegenstand der vorliegenden Erfindung ist auch ein Ver­fahren zur Herstellung des erfindungsgemäßen Molybdän­metallpulvers. Überraschenderweise läßt sich dieses in einer sehr gut kontrollierbaren Oxidation des Molybdän­metallpulvers unter einer Kohlendioxid-Atmosphäre bei unerwartet tiefen Temperaturen durchführen.The present invention also relates to a method for producing the molybdenum metal powder according to the invention. Surprisingly, this can be carried out in a very easily controllable oxidation of the molybdenum metal powder under a carbon dioxide atmosphere at unexpectedly low temperatures.

Gegenstand dieser Erfindung ist somit ein Verfahren zur Herstellung von Molybdänmetallpulver mit definiertem Sauerstoffgehalt, wobei Molybdänmetallpulver durch ther­mische Behandlung in einer Kohlendioxid-Atmosphäre bei Temperaturen unterhalb 1200°C partiell oxidiert wird. Bevorzugt erfolgt die partielle Oxidation bei Tempera­turen von 700 bis 1200°C.The subject of this invention is thus a process for the production of molybdenum metal powder with a defined oxygen content, whereby molybdenum metal powder is partially oxidized by thermal treatment in a carbon dioxide atmosphere at temperatures below 1200 ° C. The partial oxidation is preferably carried out at temperatures from 700 to 1200 ° C.

Die Sauerstoffaufnahme im Molybdänmetallpulver erfolgt nach dem erfindungsgemäßen Verfahren ausschließlich unter Bildung von MoO₂, was durch Röntgenbeugung nach­gewiesen werden kann. Bei der Reaktion wird eine äqui­valente Menge an Kohlenmonoxid freigesetzt.The oxygen uptake in the molybdenum metal powder takes place according to the method of the invention exclusively with the formation of MoO₂, which can be demonstrated by X-ray diffraction. An equivalent amount of carbon monoxide is released in the reaction.

Bei der erfindungsgemäßen Oxidationsbehandlung wird die Gewichtszunahme des Ausgangspulvers auf 12 Gew.-% be­grenzt. Der Anstieg des Partikeldurchmessers der einzel­nen Molybdänmetallpartikel entspricht dabei der Sauer­stoffaufnahme und der damit verbundenen Dichteänderung.In the oxidation treatment according to the invention, the weight increase in the starting powder is limited to 12% by weight. The increase in the particle diameter of the individual molybdenum metal particles corresponds to the oxygen uptake and the associated change in density.

Mit steigendem Kohlendioxid-Angebot und steigender Temperatur nimmt die Geschwindigkeit der Sauerstoff­aufnahme zu. Unter gleichem Kohlendioxid-Angebot und bei gleicher Reaktionstemperatur verhält sich die Sauerstoffbeladung des Molybdänmetallpulvers umgekehrt proportional zu seiner Oberfläche. Über die erwähnten Parameter sind vorgewählte Sauerstoffgehalte mit großer Genauigkeit einzustellen. In einer besonders bevorzugten Ausführungsform des erfindungsgemäßen Verfahrens wird somit der Sauerstoffgehalt des Molybdänmetallpulvers durch die Wahl der Reaktionszeit und/oder der Reaktions­temperatur und/oder der Kohlendioxid-Konzentration in der Gasatmosphäre eingestellt. Dies wird in den Fig. 1 bis 3 veranschaulicht.

  • Fig. 1 zeigt die Sauerstoff-Aufnahme eines Molybdänme­tallpulvers in Abhängigkeit von Temperatur und Zeit bei konstantem Kohlendioxid-Volumenstrom.
  • Fig. 2 zeigt die Abhängigkeit der Sauerstoff-Aufnahme eines Molybdänmetallpulvers vom Kohlendioxid-Volumen­strom und der Zeit konstanter Temperatur, gemessen am CO₂/CO-Gehalt im Abgas.
  • Fig. 3 zeigt die Abhängigkeit der Sauerstoff-Aufnahme von Molybdänmetallpulvern verschiedener Körnungen von der spezifischen Oberfläche der Pulver bei gleichem Kohlendioxid-Volumenstrom, gleicher Temperatur und Reaktionszeit.
With increasing carbon dioxide supply and increasing temperature, the rate of oxygen uptake increases. With the same carbon dioxide supply and at the same reaction temperature, the oxygen loading of the molybdenum metal powder is inversely proportional to its surface. Preselected oxygen levels can be set with great accuracy using the parameters mentioned. In a particularly preferred embodiment of the method according to the invention thus the oxygen content of the molybdenum metal powder is set by the choice of the reaction time and / or the reaction temperature and / or the carbon dioxide concentration in the gas atmosphere. This is illustrated in FIGS. 1 to 3.
  • 1 shows the oxygen uptake of a molybdenum metal powder as a function of temperature and time with a constant carbon dioxide volume flow.
  • Fig. 2 shows the dependence of the oxygen uptake of a molybdenum metal powder on the carbon dioxide volume flow and the time of constant temperature, measured by the CO₂ / CO content in the exhaust gas.
  • 3 shows the dependence of the oxygen uptake of molybdenum metal powders of different grain sizes on the specific surface of the powders with the same carbon dioxide volume flow, the same temperature and reaction time.

Durch die Sauerstoffaufnahme des Molybdänmetallpulvers tritt eine Kornvergröberung ein, die Dichte des Pulvers nimmt ab.A grain coarsening occurs due to the oxygen absorption of the molybdenum metal powder, the density of the powder decreases.

Bei der Anwendung der erfindungsgemäßen Molybdänmetall­pulver in Spritzversuchen zeigte sich eine deutliche Verbesserung der Härteeigenschaften der Auftragsschich­ten, wenn man anstelle von bekannten oxidhaltigen Mo­ lybdän-Spritzpulvern oder auch Molybdän-Spritzdraht das erfindungsgemäß sauerstoffdotierte Molybdänmetallpulver verwendet.When the molybdenum metal powders according to the invention were used in spray tests, there was a significant improvement in the hardness properties of the application layers, if instead of known oxide-containing Mo Lybdenum wettable powders or molybdenum spray wire uses the oxygen-doped molybdenum metal powder according to the invention.

Gegenstand dieser Erfindung ist somit auch die Verwen­dung des Molybdänmetallpulvers gemäß einem oder mehrerer der Ansprüche 1 bis 6 als Molybdän-Spritzpulver.This invention therefore also relates to the use of the molybdenum metal powder according to one or more of claims 1 to 6 as molybdenum wettable powder.

Im folgenden wird die Erfindung beispielhaft erläutert, ohne daß dadurch eine Einschränkung zu sehen ist.In the following, the invention is explained by way of example, without any limitation being thereby seen.

Beispielexample

800 g eines Molybdän-Metallpulvers der Körnung >5 µm und <45 µm werden in einem Röhrenofen mit 20 l/h Kohlendi­oxid begast und auf 900°C aufgeheizt.800 g of a molybdenum metal powder with a grain size of> 5 µm and <45 µm are gassed in a tube furnace with 20 l / h of carbon dioxide and heated to 900 ° C.

Nach 1 Stunde Reaktionszeit beträgt der Sauerstoffgehalt des Metallpulvers 3,6 Gew.-%, nach 2 Stunden Reaktions­zeit 4,6 Gew.-%, nach 3 Stunden Reaktionszeit 5,5 Gew-­%.After a reaction time of 1 hour, the oxygen content of the metal powder is 3.6% by weight, after 2 hours reaction time 4.6% by weight, after 3 hours reaction time 5.5% by weight.

Nachfolgend einige ausgewählte Daten des zu 3,6 % oxi­dierten Molybdänmetallpulvers und seines Ausgangsmate­rials: Ausgangsmaterial (Molybdänpulver) sauerstoffhaltiges Material Sauerstoffgehalt 0,19 % 3,6 % Dichte, pykn. 10,25 g/ml 9,49 g/ml Klopfdichte 4,80 g/ml 4,60 g/ml Schüttdichte 3,90 g/ml 3,40 g/ml Durchschnittskorngröße nach FSSS 20 µm 23 µm Here are some selected dates of the 3.6% oxidized molybdenum metal powder and its starting material: Starting material (molybdenum powder) oxygen-containing material Oxygen content 0.19% 3.6% Density, pykn. 10.25 g / ml 9.49 g / ml Tap density 4.80 g / ml 4.60 g / ml Bulk density 3.90 g / ml 3.40 g / ml Average grain size according to FSSS 20 µm 23 µm

Claims (7)

1. Molybdänmetallpulver mit einer Hülle aus Oxiden des Molybdäns, dadurch gekennzeichnet, daß die oxidi­sche Hülle aus MoO₂ besteht.1. Molybdenum metal powder with a shell made of oxides of molybdenum, characterized in that the oxide shell consists of MoO₂. 2. Molybdänmetallpulver gemäß Anspruch 1, dadurch ge­kennzeichnet, daß der Sauerstoffgehalt der Molyb­dänmetallpulver 1 bis 18, bevorzugt 2 bis 12 Gew.-­%, beträgt.2. Molybdenum metal powder according to claim 1, characterized in that the oxygen content of the molybdenum metal powder is 1 to 18, preferably 2 to 12 wt .-%. 3. Molybdänmetallpulver gemäß einem der Ansprüche 1 oder 2, dadurch gekennzeichnet, daß die mittleren Durchmesser der Molybdänmetallpulver-Einzelkörner bis 90 µm und die Dicke der MoO₂-Hülle 0,1 bis 20 µm beträgt.3. Molybdenum metal powder according to one of claims 1 or 2, characterized in that the average diameter of the individual grains of molybdenum metal powder is up to 90 µm and the thickness of the MoO₂ shell is 0.1 to 20 µm. 4. Verfahren zur Herstellung von Molybdänmetallpulver gemäß einem oder mehrerer der Ansprüche 1 bis 3, dadurch gekennzeichnet, daß Molybdänmetallpulver durch thermische Behandlung in einer Kohlendioxid-­Atmosphäre bei Temperaturen unterhalb 1200°C par­tiell oxidiert wird.4. A process for the preparation of molybdenum metal powder according to one or more of claims 1 to 3, characterized in that molybdenum metal powder is partially oxidized by thermal treatment in a carbon dioxide atmosphere at temperatures below 1200 ° C. 5. Verfahren gemäß Anspruch 4, dadurch gekennzeichnet, daß die partielle Oxidation bei Temperaturen von 700 bis 1200°C erfolgt.5. The method according to claim 4, characterized in that the partial oxidation takes place at temperatures from 700 to 1200 ° C. 6. Verfahren gemäß einem der Ansprüche 4 oder 5, da­durch gekennzeichnet, daß der Sauerstoffgehalt des Molybdänmetallpulvers durch die Wahl der Reaktions­zeit und/oder der Reaktionstemperatur und/oder der Kohlendioxidkonzentration in der Gasatmosphäre ein­gestellt wird.6. The method according to any one of claims 4 or 5, characterized in that the oxygen content of the Molybdenum metal powder is set by the choice of the reaction time and / or the reaction temperature and / or the carbon dioxide concentration in the gas atmosphere. 7. Verwendung des Molybdänmetallpulvers gemäß einem oder mehrerer der Ansprüche 1 bis 6 als Molybdän-­Spritzpulver.7. Use of the molybdenum metal powder according to one or more of claims 1 to 6 as a molybdenum wettable powder.
EP89119866A 1988-11-08 1989-10-26 Oxygenated molybdenum metal powder and process for its preparation Expired - Lifetime EP0368082B1 (en)

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AT89119866T ATE90242T1 (en) 1988-11-08 1989-10-26 OXYGENATED MOLYBDENUM METAL POWDER AND PROCESS FOR PRODUCTION THEREOF.

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DE3837782A DE3837782A1 (en) 1988-11-08 1988-11-08 OXYGENOUS MOLYBDAEN METAL POWDER AND METHOD FOR THE PRODUCTION THEREOF
DE3837782 1988-11-08

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EP0368082A2 true EP0368082A2 (en) 1990-05-16
EP0368082A3 EP0368082A3 (en) 1990-07-25
EP0368082B1 EP0368082B1 (en) 1993-06-09

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AT (1) ATE90242T1 (en)
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ES2040964T3 (en) 1993-11-01
EP0368082B1 (en) 1993-06-09
DE3837782A1 (en) 1990-05-10
US5037705A (en) 1991-08-06
DE3837782C2 (en) 1991-02-14
US4976779A (en) 1990-12-11
EP0368082A3 (en) 1990-07-25
DE58904628D1 (en) 1993-07-15
ATE90242T1 (en) 1993-06-15
JPH02185902A (en) 1990-07-20

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