Method for producing a semifinished product and semifinished product for electrical contacts and contact piece

摘要

The method relates to a method for producing a strand-like, particularly band-like semi-finished part for electrical contacts, wherein the semi-finished part has a top side intended for making the electrical contact, said top side made from a silver-based composite material in which one or multiple metal oxides or carbon are embedded, and has a carrier layer supporting the composite material made of easily solderable or weldable ignoble metal, and method having the following steps: Powder-metallurgic production of a block made from the silver-based composite material, encasing of the block made of the composite material with a powder made from the easily solderable or weldable ignoble metal, compressing the block, encased by the metal powder, to condense the metal powder, sintering the compressed block in a reducing atmosphere or in an inert atmosphere or in a vacuum, avoiding the formation of fluid eutectics from the silver of the composite material and from the non-precious metal with which the block made from the silver-based composite material is encased, reshaping of the sintered block by extrusion pressing, creating a partial strand with a top side made from composite material and a bottom side made from non-precious metal.

主权项

1. A method for producing a strand-shaped, semifinished product for electrical contacts, wherein the semifinished product has an upper face comprising a silver-based composite material intended for the electrical contact-making, one or more metal oxides or carbon being embedded in the composite material, and a carrier layer comprising easy-to-solder or easy-to-weld base metal, which carries the composite material, comprising the following steps:
producing a block from the silver-based composite material using a powder-metallurgical process; covering the block comprising the composite material with a powder of the easy-to-solder or easy-to-weld base metal; isostatically pressing the block covered with the metal powder so as to compact the metal powder; sintering the pressed block in a reducing atmosphere or in an inert atmosphere or in a vacuum preventing the formation of a liquid eutectic from the silver of the composite material and from the base metal with which the block comprising the silver-based composite material is covered; working the sintered block by extrusion molding; and generating a partial strand having an upper face comprising composite material and a lower face comprising base metal.