Electrical contact and process of manufacture
AssigneeFujitsu Limited
InventorsMasatoshi Kubo, Toshito Hara, Yuji Hayashi, Makoto Kassai, Norio Matsumoto, Tsuneyoshi Nishi, Koushichi Suzuki, Michiko Kodama, Kaduwo Sintani
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Abstract
Electrical contacts are produced by processes comprising (1) forming on a metallic body a first layer of low melting metal(s) and (2) forming on the first layer a second layer of high melting metal(s). The thus produced contacts possess prolonged life, approximately 10 times that of conventional contacts when they are operated as working contact.
Claims20
A process for producing an electrical switch contact consisting of the steps of:
- forming directly on a ferromagnetic, metallic body an inner metallic layer comprising at least one low melting temperature metal having a melting temperature lower than 500.degree. C and being selected from the group consisting of tin, lead, indium, cadmium and zinc;
- and
- forming on said inner metallic layer a single outer non-porous metallic layer comprising at least one high melting temperature metal having a melting temperature higher than 1500.degree. C, and being selected from the group consisting of rhodium, rhenium, ruthenium, iridium, tungsten and molybdenum.
A process for producing an electrical switch contact comprising the steps of:
- forming on a ferromagnetic, metallic body an inner metallic layer comprising at least one low melting temperature metal having a melting temperature lower than 500.degree. C and being selected from the group consisting of tin, lead, indium, cadmium and zinc;
- electrolytically-plating on said inner metallic layer an outer metallic layer comprising at least one high melting temperature metal having a melting temperature higher than 1500.degree. C and selected from the group consisting of rhodium, rhenium and ruthenium, and;
- heating said inner and outer metallic layers to a temperature exceeding the melting point of said low melting metal so as to produce diffusion therebetween.
A process for producing an electrical contact consisting of:
- forming directly on a ferromagnetic, metallic body an inner metallic layer comprising at least one low melting temperature metal having a melting temperature lower than 500.degree. C and selected from the group consisting of tin, lead, indium, cadmium and zinc, and;
- dry-coating on said inner metallic layer a single outer metallic layer comprising at least one high melting temperature metal having a melting temperature higher than 1500.degree. C, and selected from the group consisting of rhodium, rhenium, ruthenium, iridium, tungsten and molybdenum.
A process for producing an electrical switch contact consisting of the steps of:
- forming directly on a ferromagnetic, metallic body an inner metallic layer comprising at least one low melting temperature metal having a melting temperature lower than 500.degree. C and selected from the group consisting of tin, lead, indium, cadmium and zinc;
- heating said inner metallic layer to a temperature close to the melting temperature of said low melting temperature metal and simultaneously dry-coating on said inner metallic layer a single outer metallic layer comprising at least one high melting temperature metal having a melting temperature higher than 1500.degree. C and selected from the group consisting of rhodium, rhenium, ruthenium, iridium, tungsten and molybdenum.
Dependencies are inferred from the claim text.