EP0022980A1 - Process for manufacturing silver powder - Google Patents
Process for manufacturing silver powder Download PDFInfo
- Publication number
- EP0022980A1 EP0022980A1 EP80103900A EP80103900A EP0022980A1 EP 0022980 A1 EP0022980 A1 EP 0022980A1 EP 80103900 A EP80103900 A EP 80103900A EP 80103900 A EP80103900 A EP 80103900A EP 0022980 A1 EP0022980 A1 EP 0022980A1
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- EP
- European Patent Office
- Prior art keywords
- silver
- silver powder
- cadmium
- oxide
- 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.)
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Classifications
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- 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
- C22C1/10—Alloys containing non-metals
- C22C1/1026—Alloys containing non-metals starting from a solution or a suspension of (a) compound(s) of at least one of the alloy constituents
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/02—Contacts characterised by the material thereof
- H01H1/021—Composite material
- H01H1/023—Composite material having a noble metal as the basic material
- H01H1/0237—Composite material having a noble metal as the basic material and containing oxides
- H01H1/02372—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te
- H01H1/02374—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te containing as major component CdO
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- 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
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S75/00—Specialized metallurgical processes, compositions for use therein, consolidated metal powder compositions, and loose metal particulate mixtures
- Y10S75/956—Producing particles containing a dispersed phase
Definitions
- the invention relates to silver powder in which an oxidic or metallic phase is dispersed, and to a method for producing this powder.
- materials for electrical switch contacts should have a low tendency to sweat and a high resistance to erosion.
- the tendency to sweat and the erosion resistance of silver contacts can be significantly improved by adding oxidic phases or by adding a metallic phase that is not soluble in silver (e.g. Ni).
- the amount of such additives such as Cadmium oxide is up to 15% by weight. Spark extinguishing behavior or resistance to erosion when the power is switched off are determined by the type and quantity and degree of distribution of the additives.
- composite materials consisting of two components In addition to composite materials consisting of two components, composite materials consisting of three or more components are also used, e.g. Silver metal metal oxide or silver metal oxide (1) metal oxide (2).
- the structural parameters are in particular the corridor size distribution and the porosity.
- oxide-forming metal can be alloyed with silver. Alloy formation occurs with the exclusion of oxygen, which results in a homogeneous distribution of the oxide-forming metal in the silver. The oxide precipitates are then generated by the internal oxidation process. This process takes place e.g. application for silver and cadmium oxide materials.
- the powder metallurgical production of heterogeneous systems is usually carried out by an intimate mixture of the individual powders with subsequent pressing and sintering.
- the individual metal powders are manufactured e.g. by grinding in the solid state or by atomizing melts.
- chemical and electrolytic processes for producing one-component metal powders are known.
- the thermal decomposition of silver carbonate to fine-grain silver powder or the decomposition of nickel carbonyl at elevated temperature to the known carbonyl nickel powder For example, the thermal decomposition of silver carbonate to fine-grain silver powder or the decomposition of nickel carbonyl at elevated temperature to the known carbonyl nickel powder.
- Another method is the reduction of metal compounds, e.g. is also used to extract metal from natural ores.
- Metal powders can be produced electrolytically by a suitable choice of bath composition, bath temperature and current density and concentration of the electrolyte. Silver powder can be produced with high purity.
- a common method used in the manufacture of silver-cadmium oxide composite material is that of internal oxidation.
- the average grain size of Cadmiumoxidausscheidungen amounts to 5 / um with particle sizes of 1 to 10 / um.
- Desired homogeneous and fine-grained cadmium oxide distribution with particle sizes ⁇ 1 / um cannot be achieved with this method.
- the invention has for its object to provide silver powder which is suitable for the production of electrical contacts with low tendency to sweat, good spark suppression and good erosion behavior, and to provide a method for producing this powder.
- a silver powder to consists of particles in the size range of 1 to 10 /, the cadmium oxide as the precipitation with a grain size ⁇ 0.5 / um included, wherein for the preparation of this powder a common aqueous solution of silver and Cadmium salts, for example in a ratio of 9: 1, are atomized into a hot reactor and thermally decomposed at temperatures below the melting point of the individual components.
- the thermal decomposition takes place either in an oxidizing atmosphere (air) or in a reducing atmosphere (hydrogen, forming gas, water vapor-hydrogen mixtures).
- the homogenization of the individual components of the composite material takes place very effectively in the liquid phase.
- the solvent evaporates suddenly, leaving behind the solid constituents, in which the homogeneity of the element distribution from the liquid phase is practically retained.
- these solid particles continue to react with the surrounding gas in the hot reactor either by decomposition of the metal compound into the metal and gaseous fission products of the metal compound, or by absorption of oxygen in the corresponding metal oxide, or in the case of a reducing atmosphere by reduction Metal connections to metal.
- the process according to the invention has the advantage that no further process steps are necessary after the actual powder production. Moreover, the selection of the composite powders that can be produced is not limited by the fact that a common precipitant must be found for the components contained. The method according to the invention is therefore also very well suited for the production of more than two-component composite materials.
- Compressed air is used as the atomizing gas. With a throughput of 10 liters of solution per hour and 10 m 3 of air per hour, 1 kg of silver powder is produced per hour.
- the size of the resulting silver-cadmium oxide powder particles is between approx. 1 and 5 / um. After sintering the powder, the size of the cadmium oxide precipitates in the finished molded part is 0.2-0.5 / um.
- a mixture of 97 g of silver and 12 g of tin in a mixture of nitric acid and acetic acid is diluted to a total volume of 3.4 liters with water.
- the solution is atomized in the reactor under the same conditions as given in Example 1 and the resulting powder particles are separated from the hot exhaust gases in a centrifugal separator.
- the diameter of the silver-tin oxide particles is approximately 1/3 / .mu.m, the dimensions of the tin oxide precipitates in the sintered molded part being approximately 50 nm.
Abstract
Ein Silberpulver zur Verwendung bei elektrischen Kontakten der Zusammensetzung Ag/CdO, wobei das Pulver aus Partikeln im Grössenbereich von 1 bis 10 µm besteht, die Cadmiumoxid als Ausscheidung mit einer Korngrösse <0,5 µm enthalten, wird hergestellt durch eine wässrige Lösung von Silbersalzen und Cadmiumsalzen in einem heissen Reaktor zu zerstäuben und bei Temperaturen unterhalb des Schmelzpunktes der einzelnen Komponenten zu zersetzen.A silver powder for use in electrical contacts of the composition Ag / CdO, the powder consisting of particles in the size range from 1 to 10 μm, which contain cadmium oxide as a precipitate with a grain size <0.5 μm, is produced by an aqueous solution of silver salts and Atomize cadmium salts in a hot reactor and decompose at temperatures below the melting point of the individual components.
Description
Die Erfindung betrifft Silberpulver, in dem eine oxidische oder metallische Phase dispergiert ist, sowie ein Verfahren zur Herstellung dieses Pulvers.The invention relates to silver powder in which an oxidic or metallic phase is dispersed, and to a method for producing this powder.
Werkstoffe für elektrische Schaltkontakte sollen neben hoher elektrischer Leitfähigkeit eine geringe Schweissneigung und eine hohe Abbrandfestigkeit der Kontakte aufweisen. Schweissneigung und Abbrandfestigkeit von Silberkontakten können durch Zusätze von oxidischen Phasen oder durch Zusätze einer nicht im Silber löslichen metallischen Phase (z.B. Ni) wesentlich verbessert werden.In addition to high electrical conductivity, materials for electrical switch contacts should have a low tendency to sweat and a high resistance to erosion. The tendency to sweat and the erosion resistance of silver contacts can be significantly improved by adding oxidic phases or by adding a metallic phase that is not soluble in silver (e.g. Ni).
Der Mengenanteil derartiger Zusätze wie z.B. Cadmiumoxid beträgt bis zu 15 Gew%. Funkenlöschverhalten bzw. Abbrandfestigkeit beim Abschalten des Stromes werden durch Art und Menge sowie Verteilungsgrad der Zusätze bestimmt.The amount of such additives such as Cadmium oxide is up to 15% by weight. Spark extinguishing behavior or resistance to erosion when the power is switched off are determined by the type and quantity and degree of distribution of the additives.
Neben Verbundwerkstoffen, die aus zwei Komponenten bestehen, werden auch Verbundwerkstoffe aus drei oder mehr Komponenten eingesetzt, wie z.B. Silber-Metall-Metalloxid oder Silber-Metalloxid (1)-Metalloxid (2).In addition to composite materials consisting of two components, composite materials consisting of three or more components are also used, e.g. Silver metal metal oxide or silver metal oxide (1) metal oxide (2).
Mechanische und elektrische Eigenschaften eines elektrischen Kontaktes werden darüberhinaus durch das Kristallgefüge bestimmt. Die gefügekennzeichnenden Parameter sind insbesondere die Korrigrössenverteilung und die Porosität. Dazu kommt Homogenität und Feinheit der Fremdphasenverteilung bei mehrkomponentigen Kontaktwerkstoffen. Feinkörnigkeit und Homogenität der Fremdphasenverteilung bestimmen entscheidend das Kontaktverhalten.Mechanical and electrical properties of an electrical contact are also determined by the crystal structure. The structural parameters are in particular the corridor size distribution and the porosity. In addition, there is homogeneity and fineness of the foreign phase distribution with multi-component contact materials. Fine grain and homogeneity of the foreign phase distribution decisively determine the contact behavior.
Die Herstellung der erwähnten Verbundmaterialien ist mit üblichen Schmelzverfahren normalerweise nicht möglich, so dass pulvermetallurgische oder andere Herstellungsverfahren herangezogen werden müssen.The production of the composite materials mentioned is normally not possible with conventional melting processes, so that powder metallurgical or other production processes must be used.
Eine Ausnahme bilden solche Werkstoffe, bei denen das oxidbildende Metall mit Silber legiert werden kann. Die Legierungsbildung erfolgt unter Sauerstoffausschluss, wodurch sich eine homogene Verteilung des oxidbildenden Metalls im Silber einstellt. Die oxidischen Ausscheidungen werden dann durch das Verfahren der inneren Oxidation erzeugt. Dieses Verfahren findet z.B. bei Silber-, Cadmiumoxid-Werkstoffen Anwendung.An exception are materials in which the oxide-forming metal can be alloyed with silver. Alloy formation occurs with the exclusion of oxygen, which results in a homogeneous distribution of the oxide-forming metal in the silver. The oxide precipitates are then generated by the internal oxidation process. This process takes place e.g. application for silver and cadmium oxide materials.
Die pulvermetallurgische Herstellung heterogener Systeme erfolgt üblicherweise über eine innige Mischung der Einzelpulver mit anschliessendem Pressen und Sintern.The powder metallurgical production of heterogeneous systems is usually carried out by an intimate mixture of the individual powders with subsequent pressing and sintering.
Die Herstellung der einzelnen Metallpulver erfolgt z.B. durch Mahlen im festen Zustand oder durch Zerstäuben von Schmelzen. Darüberhinaus sind chemische und elektrolytische Verfahren zur Herstellung einkomponentiger Metallpulver bekannt.The individual metal powders are manufactured e.g. by grinding in the solid state or by atomizing melts. In addition, chemical and electrolytic processes for producing one-component metal powders are known.
So führt z.B. die thermische Zersetzung von Silbercarbonat zu feinkörnigem Silberpulver oder die Zersetzung von Nickelcarbonyl bei erhöhter Temperatur zu dem bekannten Carbonyl-Nickelpulver.For example, the thermal decomposition of silver carbonate to fine-grain silver powder or the decomposition of nickel carbonyl at elevated temperature to the known carbonyl nickel powder.
Naßchemische Verfahren, wie die Fällung aus wässriger Lö- sung, werden bei Edelmetallen, wie Silber oder Gold, angewendet.Wet chemical methods, such as precipitation from aqueous solution L ö- are precious metals such as silver or gold, applied.
Ein weiteres Verfahren ist die Reduktion von Metallverbindungen, die z.B. auch zur Metallgewinnung aus natürlichen Erzen herangezogen wird.Another method is the reduction of metal compounds, e.g. is also used to extract metal from natural ores.
Elektrolytisch können Metallpulver durch geeignete Wahl von Badzusammensetzung, Badtemperatur und Stromdichte sowie Konzentration des Elektrolyten hergestellt werden. Silberpulver lässt sich dabei mit hoher Reinheit herstellen.Metal powders can be produced electrolytically by a suitable choice of bath composition, bath temperature and current density and concentration of the electrolyte. Silver powder can be produced with high purity.
Darüberhinaus ist die Verdüsung von Metallschmelzen oder homogenen Legierungsschmelzen zur Herstellung von Metallpulvern bekannt.In addition, the atomization of metal melts or homogeneous alloy melts for the production of metal powders is known.
Alle oben genannten Verfahren eignen sich jedoch nicht zur direkten Herstellung von Metallpulvern mit oxidischen oder mit metallischen Fremdphasen. Gewisse Erfolge wurden durch die gemeinsame Fällung zweier Komponenten aus wässriger Lösung erzielt. So können z.B. Silber und Nickel aus einer Nitratlösung gemeinsam als Carbonate gefällt werden. Um daraus die heterogene Metallegierung herzustellen, ist jedoch ein weiterer thermischer Verfahrensschritt notwendig, bei dem die Carbonate thermisch zersetzt werden. Ausser diesem wirtschaftlichen Nachteil ergibt sich auch ein technischer Nachteil des Verfahrens dadurch, dass bei der thermischen Zersetzung der Carbonate die feinkörnigen Metallpulver zum Zusammensintern neigen, d.h. es findet bereits vor dem eigentlichen Sinterprozess eine Agglomeration statt.However, all of the above methods are not suitable for the direct production of metal powders with oxidic or with metallic foreign phases. Some success was achieved by co-precipitating two components from an aqueous solution. For example, Silver and nickel from a nitrate solution are precipitated together as carbonates. In order to produce the heterogeneous metal alloy from this, however, a further thermal process step is necessary in which the carbonates are thermally decomposed. In addition to this economic disadvantage, there is also a technical disadvantage of the process in that the fine-grained metal powders tend to sinter together during the thermal decomposition of the carbonates, i.e. agglomeration takes place before the actual sintering process.
Ein häufig in der Praxis für die Herstellung von Silber-Cadmiumoxid-Verbundmaterial angewandtes Verfahren ist das der inneren Oxidation. Die mittlere Korngrösse der Cadmiumoxidausscheidungen beträgt dabei 5 /um mit Teilchengrössen zwischen 1 und 10 /um. Die im Interesse einer guten Funken- 'löschung gewünschte homogene und feinkörnige Cadmiumoxidverteilung mit Partikelgrössen < 1 /um lässt sich mit diesem Verfahren nicht erreichen. Darüberhinaus ergibt sich eine Inhomogenität der Cadmiumoxidteilchengrössen als Funktion des Abstandes von der Phasengrenzfläche Legierung-Luft, die auf die Diffusion von Cadmium in Richtung zur Oberfläche zurückzuführen ist.A common method used in the manufacture of silver-cadmium oxide composite material is that of internal oxidation. The average grain size of Cadmiumoxidausscheidungen amounts to 5 / um with particle sizes of 1 to 10 / um. In the interest of a good spark '' Desired homogeneous and fine-grained cadmium oxide distribution with particle sizes <1 / um cannot be achieved with this method. In addition, there is an inhomogeneity of the cadmium oxide particle sizes as a function of the distance from the alloy-air phase interface, which is due to the diffusion of cadmium towards the surface.
Alle pulvermetallurgischen Verfahren, bei denen von einkomponentigen Metallen bzw. Oxid ausgegangen wird, liefern wesentlich gröbere Ausscheidungen der zweiten Phase. Dies ist darauf zurückzuführen, dass entweder die Ausgangspartikelgrössen der Einzelpulver zu gross sind oder beim Mahl- und Mischvorgang die Agglomeration gleichartiger Teilchen nicht verhindert werden kann.All powder metallurgical processes, which are based on single-component metals or oxide, produce much coarser precipitations in the second phase. This is due to the fact that either the starting particle sizes of the individual powders are too large or that the agglomeration of similar particles cannot be prevented during the grinding and mixing process.
Der Erfindung liegt die Aufgabe zugrunde, Silberpulver zu schaffen, das zur Herstellung von elektrischen Kontakten mit geringer Schweissneigung, guter Funkenlöschung und gutem Abbrandverhalten geeignet ist, sowie ein Verfahren zur Herstellung dieses Pulvers anzugeben.The invention has for its object to provide silver powder which is suitable for the production of electrical contacts with low tendency to sweat, good spark suppression and good erosion behavior, and to provide a method for producing this powder.
Die Aufgabe wird erfindungsgemäss durch ein Silberpulver gelöst, das aus Partikeln im Grössenbereich von 1 bis 10 /um besteht, die Cadmiumoxid als Ausscheidung mit einer Korngrösse < 0,5 /um enthalten, wobei zur Herstellung dieses Pulvers eine gemeinsame wässrige Lösung von Silber- und Cadmiumsalzen z.B. im Verhältnis 9 : 1 in einen heissen Reaktor zerstäubt wird und bei Temperaturen unterhalb des Schmelzpunktes der einzelnen Komponenten thermisch zersetzt wird. Die thermische Zersetzung erfolgt je nach Materialzusammensetzung und gewünschtem Endprodukt entweder in einer oxidierenden Atmosphäre (Luft) oder einer reduzierenden Atmosphäre (Wasserstoff, Formiergas, Wasserdampf-Wasserstoffgemische).The object is achieved according to the invention by a silver powder to consists of particles in the size range of 1 to 10 /, the cadmium oxide as the precipitation with a grain size <0.5 / um included, wherein for the preparation of this powder a common aqueous solution of silver and Cadmium salts, for example in a ratio of 9: 1, are atomized into a hot reactor and thermally decomposed at temperatures below the melting point of the individual components. Depending on the material composition and the desired end product, the thermal decomposition takes place either in an oxidizing atmosphere (air) or in a reducing atmosphere (hydrogen, forming gas, water vapor-hydrogen mixtures).
Bei dem erfindungsgemässen Verfahren erfolgt die Homogenisierung der Einzelkomponenten des Verbundwerkstoffes sehr effektiv in der flüssigen Phase. Beim Einsprühen der gemeinsamen Lösung in den heissen Reaktor verdampft das Lösungsmittel schlagartig unter Zurücklassung der festen Bestandteile, in denen die Homogenität der Elementverteilung aus der flüssigen Phase praktisch erhalten bleibt. Die Weiterreaktion dieser Feststoffpartikel mit dem umgebenden Gas im heissen Reaktor erfolgt je nach Gaszusammensetzung und Material entweder durch Zerfall der Metallverbindung in das Metall und gasförmige Spaltprodukte der Metallverbindung, oder durch Aufnahme von Sauerstoff in das entsprechende Metalloxid, oder im Fall reduzierender Atmosphäre durch Reduktion-der Metallverbindungen zum Metall. Da nach der Verdampfung des Lösungsmittels keine schmelzflüssigen Phasen in den einzelnen Partikeln auftreten, erfolgt die Agglomeration einzelner Komponenten im Verbundmaterial nur durch relativ langsame Diffusionsprozesse. Die kurze Verweilzeit der Partikel in der heissen Reaktionszone (einige Sekunden) lässt ein Kornwachstum über den Bereich von 1 /um nicht zu.In the method according to the invention, the homogenization of the individual components of the composite material takes place very effectively in the liquid phase. When the common solution is sprayed into the hot reactor, the solvent evaporates suddenly, leaving behind the solid constituents, in which the homogeneity of the element distribution from the liquid phase is practically retained. Depending on the gas composition and material, these solid particles continue to react with the surrounding gas in the hot reactor either by decomposition of the metal compound into the metal and gaseous fission products of the metal compound, or by absorption of oxygen in the corresponding metal oxide, or in the case of a reducing atmosphere by reduction Metal connections to metal. Since there are no molten phases in the individual particles after the evaporation of the solvent, the agglomeration of individual components in the composite material takes place only through relatively slow diffusion processes. The short residence time of the particles in the hot reaction zone (a few seconds) does not allow grain growth over the range of 1 / um.
Im Vergleich zu den konkurrierenden-Fällungsverfahren bietet das erfindungsgemässe Verfahren den Vorteil, dass nach der eigentlichen Pulverherstellung keine weiteren Verfahrensschritte mehr notwendig sind. Im übrigen ist die Auswahl der herstellbaren Verbundpulver nicht dadurch begrenzt, dass ein gemeinsames Fällungsmittel für die enthaltenen Komponenten gefunden werden muss. Das erfindungsgemässe Verfahren eignet sich daher auch sehr gut zur Herstellung von mehr als zweikomponentigen Verbundwerkstoffen.Compared to the competing precipitation processes, the process according to the invention has the advantage that no further process steps are necessary after the actual powder production. Moreover, the selection of the composite powders that can be produced is not limited by the fact that a common precipitant must be found for the components contained. The method according to the invention is therefore also very well suited for the production of more than two-component composite materials.
Darüberhinaus ist das Auswaschen von Fällungsmitteln nach der Pulverherstellung bei dem erfindungsgemässen Verfahren nicht notwendig.In addition, it is not necessary to wash out precipitants after powder production in the process according to the invention.
Eine Lösung von 611,52 g Silbernitrat (AgN03) und 103,67 g Cadmiumnitrat (Cd (NO3)2 x 4 H20) in 4 Liter Wasser wird mit Hilfe pneumatischer Zweistoffdüsen in einen Rohrreaktor der Abmessungen 0,3 m 0, 1,5 m Länge eingesprüht, wobei die Wandtemperatur des Reaktors 950° C beträgt. Als Zerstäubergas wird Pressluft verwendet. Bei einem Durchsatz von 10 Liter Lösung pro Stunde und 10 m3 Luft pro Stunde wird 1 kg Silberpulver pro Stunde hergestellt. Die Grösse der entstandenen Silber-Cadmium-Oxidpulverpartikel liegt zwischen ca. 1 und 5 /um. Nach dem Sintern des Pulvers beträgt die Grösse der Cadmiumoxidausscheidungen im fertigen Formteil 0,2 - 0,5 /um.A solution of 611.52 g of silver nitrate (AgN0 3 ) and 103.67 g of cadmium nitrate (Cd (NO 3 ) 2 x 4 H 2 0) in 4 liters of water sprayed with the aid of pneumatic two-component nozzles into a tubular reactor measuring 0.3 m 0.1.5 m in length, the wall temperature of the reactor being 950 ° C. Compressed air is used as the atomizing gas. With a throughput of 10 liters of solution per hour and 10 m 3 of air per hour, 1 kg of silver powder is produced per hour. The size of the resulting silver-cadmium oxide powder particles is between approx. 1 and 5 / um. After sintering the powder, the size of the cadmium oxide precipitates in the finished molded part is 0.2-0.5 / um.
Eine Mischung von 97 g Silber und 12 g Zinn in einer Mischung von Salpetersäure und Essigsäure wird auf ein Gesamtvolumen von 3,4 Liter mit Wasser verdünnt. Die Lösung wird unter denselben Bedingungen, wie in Beispiel 1 angeführt, im Reaktor zerstäubt und die entstandenen Pulverpartikel werden in einem Zentrifugalabscheider von den heissen Abgasen getrennt. Der Durchmesser der Silber-Zinn-Oxidpartikel beträgt ca. 1 - 3 /um, wobei im gesinterten Formteil die Abmessungen der Zinn-Oxidausscheidungen ca. 50 nm betragen.A mixture of 97 g of silver and 12 g of tin in a mixture of nitric acid and acetic acid is diluted to a total volume of 3.4 liters with water. The solution is atomized in the reactor under the same conditions as given in Example 1 and the resulting powder particles are separated from the hot exhaust gases in a centrifugal separator. The diameter of the silver-tin oxide particles is approximately 1/3 / .mu.m, the dimensions of the tin oxide precipitates in the sintered molded part being approximately 50 nm.
Claims (7)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2929630 | 1979-07-21 | ||
| DE2929630A DE2929630C2 (en) | 1979-07-21 | 1979-07-21 | Process for the production of silver powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0022980A1 true EP0022980A1 (en) | 1981-01-28 |
| EP0022980B1 EP0022980B1 (en) | 1985-09-04 |
Family
ID=6076411
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP80103900A Expired EP0022980B1 (en) | 1979-07-21 | 1980-07-09 | Process for manufacturing silver powder |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US4396420A (en) |
| EP (1) | EP0022980B1 (en) |
| JP (1) | JPS5651501A (en) |
| DE (1) | DE2929630C2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0283536A1 (en) * | 1987-03-24 | 1988-09-28 | INOVAN GmbH & Co. KG Metalle und Bauelemente | Process for making silver/MeO contact plates with a solderable or weldable backing |
| EP0299099A1 (en) * | 1987-07-14 | 1989-01-18 | INOVAN GmbH & Co. KG Metalle und Bauelemente | Method of making silver/Me0 contact plates with a weldable or solderable backing |
| US4863514A (en) * | 1985-09-11 | 1989-09-05 | Degussa Atiengesellschaft | Material for facing denture |
| US5284527A (en) * | 1992-01-21 | 1994-02-08 | United Technologies Corporation | Method of making silver-metal oxide materials and electrical contacts |
| EP0662521A2 (en) * | 1994-01-05 | 1995-07-12 | E.I. Du Pont De Nemours And Company | Method for making silver-palladium alloy powders by areosol decomposition |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3715979A1 (en) * | 1985-11-13 | 1988-12-08 | Mtu Muenchen Gmbh | Process for producing dispersion-hardened metal alloys |
| DE3621398C1 (en) * | 1986-06-26 | 1987-11-19 | Dornier System Gmbh | Process for the preparation of a suspension containing highly concentrated aqueous silver and tin salts |
| DE3622123A1 (en) * | 1986-07-02 | 1988-01-21 | Dornier System Gmbh | METHOD AND DEVICE FOR PRODUCING COMPOSITE POWDERS |
| US4911769A (en) * | 1987-03-25 | 1990-03-27 | Matsushita Electric Works, Ltd. | Composite conductive material |
| DE3734178A1 (en) * | 1987-10-09 | 1989-04-20 | Duerrwaechter E Dr Doduco | POWDER METALLICALLY PRODUCED MATERIAL FOR ELECTRICAL CONTACTS MADE OF SILVER WITH GRAPHITE AND METHOD FOR THE PRODUCTION THEREOF |
| ES2080052T3 (en) * | 1988-04-16 | 1996-02-01 | Duerrwaechter E Dr Doduco | POWDER METALLURGICAL PROCEDURE FOR THE PRODUCTION OF A SEMI-TERMINATED PART FOR ELECTRICAL CONTACTS MADE OF A SILVER BASED COMPOSITE MATERIAL, WITH IRON. |
| FR2639466B1 (en) * | 1988-11-22 | 1991-02-15 | Telemecanique | PROCESS FOR PREPARING AN ELECTRICAL CONTACT MATERIAL AND METHOD FOR MANUFACTURING A CONTACT ELEMENT INCORPORATING SUCH A MATERIAL |
| ATE136394T1 (en) * | 1992-06-10 | 1996-04-15 | Duerrwaechter E Dr Doduco | MATERIAL FOR ELECTRICAL CONTACTS BASED ON SILVER-TIN OXIDE OR SILVER-ZINC OXIDE |
| TW256798B (en) * | 1992-10-05 | 1995-09-11 | Du Pont | |
| TW261554B (en) * | 1992-10-05 | 1995-11-01 | Du Pont | |
| DE19503182C1 (en) * | 1995-02-01 | 1996-05-15 | Degussa | Sintered material used as electrical contacts for switching amperage rating |
| US5846288A (en) * | 1995-11-27 | 1998-12-08 | Chemet Corporation | Electrically conductive material and method for making |
| US6159267A (en) * | 1997-02-24 | 2000-12-12 | Superior Micropowders Llc | Palladium-containing particles, method and apparatus of manufacture, palladium-containing devices made therefrom |
| US6699304B1 (en) * | 1997-02-24 | 2004-03-02 | Superior Micropowders, Llc | Palladium-containing particles, method and apparatus of manufacture, palladium-containing devices made therefrom |
| US6165247A (en) * | 1997-02-24 | 2000-12-26 | Superior Micropowders, Llc | Methods for producing platinum powders |
| US6338809B1 (en) | 1997-02-24 | 2002-01-15 | Superior Micropowders Llc | Aerosol method and apparatus, particulate products, and electronic devices made therefrom |
| US6268014B1 (en) * | 1997-10-02 | 2001-07-31 | Chris Eberspacher | Method for forming solar cell materials from particulars |
| US20050097987A1 (en) * | 1998-02-24 | 2005-05-12 | Cabot Corporation | Coated copper-containing powders, methods and apparatus for producing such powders, and copper-containing devices fabricated from same |
| TWI237064B (en) * | 2002-03-25 | 2005-08-01 | Ind Tech Res Inst | Supported metal catalyst for synthesizing carbon nanotubes by low-temperature thermal chemical vapor deposition and method of synthesizing nanotubes using the same |
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| GB960592A (en) * | 1959-11-12 | 1964-06-10 | Handy & Harman | Alloys and electric contacts formed therefrom |
| US3451810A (en) * | 1967-08-01 | 1969-06-24 | Lucas Industries Ltd | Method of manufacturing oxygen electrodes by sintering ag and an ag-cd alloy |
| US3501287A (en) * | 1968-07-31 | 1970-03-17 | Mallory & Co Inc P R | Metal-metal oxide compositions |
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| GB1462049A (en) * | 1973-05-18 | 1977-01-19 | Atomic Energy Authority Uk | Production of metal-containing material in particulate form |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US4863514A (en) * | 1985-09-11 | 1989-09-05 | Degussa Atiengesellschaft | Material for facing denture |
| EP0283536A1 (en) * | 1987-03-24 | 1988-09-28 | INOVAN GmbH & Co. KG Metalle und Bauelemente | Process for making silver/MeO contact plates with a solderable or weldable backing |
| EP0299099A1 (en) * | 1987-07-14 | 1989-01-18 | INOVAN GmbH & Co. KG Metalle und Bauelemente | Method of making silver/Me0 contact plates with a weldable or solderable backing |
| US5284527A (en) * | 1992-01-21 | 1994-02-08 | United Technologies Corporation | Method of making silver-metal oxide materials and electrical contacts |
| EP0662521A2 (en) * | 1994-01-05 | 1995-07-12 | E.I. Du Pont De Nemours And Company | Method for making silver-palladium alloy powders by areosol decomposition |
| EP0662521A3 (en) * | 1994-01-05 | 1995-10-11 | Du Pont | Method for making silver-palladium alloy powders by areosol decomposition. |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2929630C2 (en) | 1983-12-15 |
| JPS5651501A (en) | 1981-05-09 |
| DE2929630A1 (en) | 1981-01-29 |
| EP0022980B1 (en) | 1985-09-04 |
| US4396420A (en) | 1983-08-02 |
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