Siemens Aktiengesellschaft

Heinrich Hassler

Horst Schreiner

Horst Kippenberg

Joachim Grosse

Helmut Freller

Ludwig Schultz

Peter Schack

Gunter Tiefel

Joachim Hannich

Gert Fischer

Hans-Joachim Lippmann

Reiner Muller

A method of producing copper-chromium fusion alloys having a chromium content of at least 25% by mass and at most 60% by mass with a homogeneous macrostructure without lattice defects and without shrink holes or pipes, which can be used as contact material for vacuum power switches with breaking currents exceeding 10kA. According to the invention, during fusing of the starting material to the fusion alloy a superheating to at least 2000.degree. C. is obtained at least in a partial zone of the instantaneous melt volume. Thereafter the melt is cooled at a cooling rate such that no primary Cr precipitation or segregation occurs.

Method of producing copper-chromium fusion alloys as contact material

A simplified, easily producible, strongly adherent, solderable and corrosion resistant layer system for opto-electronic displays is produced by vapor deposition techniques. In accordance with the invention, the layer system is formed of two layers; a transparent first layer formed of a nonsolderable oxide semiconductor, such as In.sub.2 O.sub.3 SnO.sub.2, and a second layer formed of a solderable, oxidation-resistant material, which is formed at least partially of a copper alloy containing an alloying additive consisting of a metal which is less noble than copper, illustratively CuMg.

Layer system for opto-electronic displays

A device for manufacturing a laminated semifinished material by indirect extrusion of a sintered-bond blank consisting of layers of metal, metal alloys, metal mixtures or mixtures of metals and nonmetals comprises a vessel with a rectangular cutout or extrusion chamber and a one- or multipart extrusion die with one or several cutouts. A surface of the die facing the blank is profiled in the form of one or more roof gables, the surfaces of which gable forms extend perpendicularly towards the cutout from a sliding surface of the extrusion die.

Device for manufacturing laminated semifinished material

A method of manufacturing a contact bridge for an electric switching apparatus which contact bridge includes an electrically highly conductive overlay and a concave-shaped support layer. The method comprises the steps of pressing a powder blank comprising two layers of metallic material, one of which comprises iron for the support layer and the other of which comprises copper for the overlay; sintering the blank in a protective gas; sizing the blank; further sintering the blank in a protective gas; further pressing the blank by reverse-flow cup extrusion; and applying an electrical contact to the overlay. Alternatively, the powder blank may comprise a layer of copper-zirconium and silver-metal oxide, the latter for an electrical contact layer. In this embodiment, the contact bridge is formed with the electrical contact in one step and there is no need to apply a contact to the bridge after the pressing by reverse-flow cup extrusion.

Method of manufacturing a contact bridge

The invention relates to a sintered composite material as the contact material for medium-voltage vacuum power circuit breakers, particularly in the switching voltage range from 7.2 kV to 36 kV. The contact material is comprised of a sintered composite of a burn-off-resistant metal component such as iron, cobalt, chromium, nickel, zirconium or alloys or mixtures of these metals, and a component which lowers the breaking current. As the breaking current-lowering component are provided metals, compounds or alloys of metals having a boiling point above 2400.degree. C. such as, for example, tin, chromium carbide (Cr.sub.3 C.sub.2) or copper zirconide (ZrCu.sub.4, ZrCu.sub.3).

Sintered composite material as contact material for medium-voltage

A method for producing multilayered contacts for medium-voltage vacuum power circuit breakers is provided comprising impregnating under vacuum with oxygen-free, liquid copper, a composite body of metal powders consisting of at least 35% by volume of a metal selected from the group consisting of chromium and vanadium and at least one metal selected from the group consisting of chromium, vanadium, cobalt, nickel and iron, in a crucible comprised of a metal selected from the group consisting of iron, steel, and chromium-nickel steel; and removing at least part of the crucible to expose a contact surface.

Method for the manufacture of multilayered contacts for medium-voltage

A contact material for vacuum switches comprising a composite inclusion metal of at least two metal components in which a first component has an electric conductivity of at least 10 m/ohm mm.sup.2, the share of this component being between 35 and 60% by volume. At least one component has a melting point of at least 1400.degree. C and at least one component is effective as a getter. These components are embedded in the first component, with only isolated bridges existing between the finely distributed inclusions. The porosity of the composite inclusion metal is less than 2% by volume.

Composite metal as a contact material for vacuum switches

A new material for making the electrical contacts of high-power vacuum circuit breakers comprises an alloy having as a base metal, a metal such as copper, nickel, iron, cobalt or titanium, and as an alloying metal, a metal such as bismuth, tellurium or lead, this alloy also including an auxiliary metal which forms a eutectic with the base metal used. The alloy has a fine grain size while at the same time a low gas content.

Contact material for high-power vacuum circuit breakers

An impregnated compound metal is provided comprising a metal matrix comprising a metallic main constituent having a melting point above 1400.degree. C and a metallic embrittlement additive impregnated with an impregnating metal or metal alloy, brittle intermetallic phases or mixed crystals forming between the main constituent and the embrittlement additive at sintering temperatures above 1200.degree. C. The percentage of embrittlement additive relative to the main constituent is 0.5 to 10 percent by weight. The melting points of all constituents are above 2000.degree. C.

Impregnated compound metal as contact material for vacuum switches and

A method of fabricating a contact material for high-power vacuum circuit breakers. In the method, an alloy consisting essentially of a base metal having a melting point above about 1000.degree. C and below about 1800.degree. C, at least one alloying metal which will not form a solid solution with the base metal, and at least one auxiliary metal which forms a eutectic with the base metal are melted under vacuum at a temperature between about 1000.degree. C and about 1800.degree. C. The molten alloy is then slowly cooled so as to form fine grain crystals of the base metal and auxiliary metal in solid solution in the eutectic while the eutectic is a liquid and transfer gases expelled from the crystals during the cooling to the liquid eutectic to increase the concentration of gases in the liquid eutectic above an equilibrium concentration, cause evacuation of the gases from the liquid eutectic, and remove the gases from the alloy. The alloy is then cooled to rapidly solidify the liquid eutectic and precipitate the alloying metal as a fine dispersion in the eutectic.

Method of fabricating a contact material for high-power vacuum circuit

Electric contact material having good solderability, consists of a porous matrix of sintered powder particles of a refractory metal, such as tungsten or molybdenum, with its pores impregnated with a metal alloy consisting of a telluride-forming metal, such as copper, silver or lead, and a sufficient amount of a telluride of such metal to form a brittle deposit of tellurium and the telluride-forming metal, both in elemental form, on the material's surface, apparently produced by decomposition and vaporization of the telluride due to electrical arcing, and which vapor after the arcing and rapid cooling of the material, condenses on the material's surface to form the deposit. This brittle deposit provides an effective reduction in the contact welding force of the material as compared to prior art electric contact materials of good solderability.

Telluride containing impregnated electric contact material

An electric contact material comprises a matrix formed by refractory metal powder particles having interbonding portions and defining pores infiltrated by a solidified molten metal impregnant. The interbonding portions are formed by a solidified molten alloy formed by the refractory metal and an alloying metal, and has a melting temperature above the impregnant's melting temperature. The alloying metal is present in an amount that is small relative to that of the refractory metal but which is effective for the formation of the interbonding portions by the alloy. The material may be made by cold molding the refractory metal powder particles and powder particles of the alloying metal, to form a compact which is then sintered without being under pressure. The interbonding alloy forms during the sintering, and when solidified, forms the interbonding portions between the particles defining the pores. By infiltration these portions are filled with the molten impregnating metal.

Growing community of inventors

Wendelstein, Germany

Heinrich Hassler