Powder-metallurgical process for producing a semifinished product for electric contacts from a silver-based composite with iron

摘要

A powder-metallurgical process for producing a semifinished product for electric contacts from a silver-based composite with iron is described. The composite consists of 5 to 50% by weight of iron as first secondary constituent and of 0 to 5% by weight of a second secondary constituent consisting of one or more of the metals titanium, zirconium, niobium, tantalum, molybdenum, tungsten, manganese and zinc and/or oxides thereof and/or carbides thereof, the remainder being silver as the main constituent. Initially, a composite powder or - if possible - an alloy powder is prepared from at least two different constituents of the composite, one of which is silver or iron, in particular by the spray pyrolysis process, and this is then mixed, if appropriate, with the remaining constituents of the composite in powder form, pressed and sintered.