Abstract: Purely powder-metallurgical processes or sinter-impregnation processes are often used to manufacture CuCr contact materials. Here the aim is to obtain the lowest possible residual porosity, which should be <1%. According to the invention, a powder moulding of the components is densified in two stages; the first stage is a sintering process with a densification of the sintered body to a closed porosity, and the second stage is a hot-isostatic pressing operation (HIP), in which the unencased workpieces are taken to a final density amounting to a space occupation of at least 99%. Thus, an economical method of manufacturing high grade material is obtained. It is possible to produce multi-layer contacts or self-adhesive bonds between the sintered body and a solid substrate, e.g. a copper contact bolt.

Abstract: A vacuum switching tube contains a switching chamber and a first contact piece fixed in place in it, as well as a movable current conducting rod with a second contact piece and a ring-shaped insulator. According to the present invention, the ring-shaped insulator has at least one end surface on the vacuum side, which is at least partially free of metallization, and which faces away from the metal vapor formed during switching and is therefore protected against condensation. It is advantageous if a gap with a pre-determined length and height is formed by the end surface of the insulator and by at least one adjacent metallic flange.

Abstract: To produce CuCr contact materials, it is known to use purely powder-metallurgical, sinter impregnation and smelt-metallurgical processes. Only materials produced by smelt-metallurgical processes are suitable as contact materials for vacuum contactors based on copper-chromium. According to the invention, a contact material for vacuum contactors consisting essentially of copper (Cu) and chromium (Cr) in the proportion of 50 to 70% wt. Cu and 30 to 50% wt. Cr is manufactured by pressing and sintering a powdered mixture of the components until a closed porosity is attained and by subsequently cold working the sintered body. It has been possible to demonstrate that an intimate and faultless bonding of the components Cu and Cr is obtained by cold welding the structural constituents with this process as with smelting.

Abstract: Contact pieces for vacuum switches with axial magnetic field are designed e.g. as cup contacts with slotting in the same direction which support a diskshaped contact body and have means for the suppression of eddy currents. According to the invention, the contact bodies (10, 20, 30, 40, 50) have, at least on their backside, radial areas (15, 25, 35, 45, 55) of markedly lower electrical conductivity than the base material. Such radial areas may be, grooves (15 to 18) on the backside (12) of the contact body (10), diffusion zones (25, 35) of additives reducing the electrical conductivity of the base material, or combinations of the two. If the contact bodies (40,50) are made by powder metallurgical methods, it is also possible to provide the radial areas during production as fillings (45) or as molded parts (55) of a material of lower electrical conductivity than that of the base material.

Abstract: The invention relates to a method for the production of a filled layer component made out of a monolithic ceramic body by impregnating a ceramic layer body of dense and porous layers with liquid impregnating material which wets the ceramic and by applying contacts. According to the invention the contacts are applied following the impregnation process without any further intermediate steps, and an electrical bonding of the contacts to the metal filler takes place.

Abstract: A method for manufacturing melt materials of copper, chromium, and at least one readily evaporable component as well as a fusible electrode for using this method is disclosed.More specifically, an arc melting method is used for the manufacture of melt materials based on copper and chromium in which the electrode material melting off a fusible electrode of given resultant composition is collected in a water-cooled permanent mold for the purpose of cooling down without macroscopic separation of copper and chromium.A fusible electrode for use in this method is also provided. This fusible electrode partially consists of a solid alloy of copper with the readily evaporable component.

Abstract: A sintered monolithic ceramic body of a filler layer component has cavities which are open at end faces alternating from layer to layer and which has openings toward the lateral faces. The cavities contain ceramic particles distributed in the volume to provide support elements and the cavities are completely filled with a metal or metal alloy having a melting temperature considerably lower than the sintering temperature of the ceramic body. The metal or metal alloy exhibits the property of wetting the surfaces of the ceramic layers in the cavity in its molten condition. Contacts are applied at the end faces of the ceramic body and the openings in the lateral faces of the body are limited so that the contacts do not electrically contact the metal or metal alloy filling at the lateral faces.

Abstract: The invention relates to a filler layer component for a monolithic ceramic body having a ceramic layer structure of dense and porous layers which is impregnated with a metallic material. According to the invention, one selects as impregnating material a metal or alloy which in its liquid state wets the ceramic. This may be in particular a lead-indium, a copper-indium, or a silver-indium alloy in which the indium content is greater than 0.5%.

Abstract: The invention relates to a filled layer component made out of monolithic ceramic, in particular a capacitor, having a ceramic layer structure of dense and porous layers which is impregnated with a metallic material and is provided with contacts on the outer faces. According to the invention, the contacts have at least on their surfaces enrichments with constituents which form with the material of the contacts one or more intermetallic compounds which are largely insoluble in the impregnating material. These enrichments can be applied in a first manufacturing method before the impregnation process, or in another manufacturing method during the impregnation process.

Abstract: This invention relates to a new use of a fused material of copper and chrome as a contact material for use in vacuum contactors. In addition, the invention relates also to the contact material itself and to the method of its fabrication, as well as for special contact arrangements in the vacuum contactors.The invention shows a whole new, unsuspected range of application for the above fused materials. Up to now, contactors normally used material based on tungsten and copper which were first sintered and then immersed. It has now been experimentally shown that fused materials of copper and chrome, particularly after being reshaped, are very well suited as a contact material for vacuum contactors. Furthermore, in contact pieces of said fused material, methods are provided for additional additives to be precisely inserted by localized alloying, diffusion, or related techniques.

Abstract: Contact pieces for vacuum switchgear comprise a base material with additives of readily vaporizable components to produce a sufficiently conductive switch path in the switch-off process. It is desired to have an overvoltage-free switching behavior for the vacuum switchgear. The additives are concentrated in a firmly adhering layer covering the switching surface of the contact piece. Such contact pieces can be manufactured in particular by direct fusing of the additives on the surface, by fusing a separate application of the additives in powder form, in granulate form or as foil or sheet on the surface or alternatively by vapor deposition of the additives on the switching surface of a given contact piece body of base material. Advantageously, a CuCr contact piece base material is used.

Abstract: 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.

Abstract: In the method according to the invention, Cr powder is poured into a degased mold, which can be made of graphite. On this Cr powder a piece of low-oxygen copper is placed. Subsequently, the mold is closed with a porous cover, which can also be made of graphite. Then the mold is degased in a high-vacuum furnace at room temperature until a pressure of better than 10.sup.-4 mb is reached. Thereafter, the furnace temperature is increased to as high as possible a temperature below the melting point of copper. This furnace temperature is maintained constant until an internal pressure in the furnace of better than 10.sup.-4 mb is reached. Subsequently, without intermediate cooling, the furnace temperature is further increased slowly to a final value of 100 degrees K. to 200 degrees K. above the melting temperature of the copper. This temperature is then maintained until the porosity contained in the Cr powder is completely filled up by the liquid copper.

Abstract: 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).

Abstract: 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.

Abstract: 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.

Abstract: 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.