Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
  • C22C32/001—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides
  • C22C32/0015—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ with only oxides with only single oxides as main non-metallic constituents
  • C22C32/0021—Matrix based on noble metals, Cu or alloys thereof
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H1/00—Contacts
  • H01H1/02—Contacts characterised by the material thereof
  • H01H1/021—Composite material
  • H01H1/023—Composite material having a noble metal as the basic material
  • H01H1/0237—Composite material having a noble metal as the basic material and containing oxides
  • H01H1/02372—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te
  • H01H1/02376—Composite material having a noble metal as the basic material and containing oxides containing as major components one or more oxides of the following elements only: Cd, Sn, Zn, In, Bi, Sb or Te containing as major component SnO2

Definitions

• the invention relates to a silver contact material for producing contacts usable for direct and alternating current, in particular for producing contact wire, which is suitable for direct riveting into contact pieces (contact springs).
• Silver and silver alloys are primarily used to produce high-voltage contacts, which not only have good mechanical and electrical properties, but are also economical to produce.
• pure silver is unsuitable for many applications because of its tendency to weld when switching, its further tendency to stick at high contact pressure, and finally also because of the expected material migration when switching direct current.
• its mechanical abrasion resistance and erosion resistance are limited.
• Silver alloys are therefore used to an ever increasing extent, which reduce or even completely avoid these disadvantages inherent in pure silver.
• Preferred silver-nickel composites have a nickel content between 10% by weight and 40% by weight.
• Composites of this type exhibit high hardness and strength, good electrical and thermal conductivity and, as a high-current contact - also with good burn-off resistance - even with direct current.
• the erosion residues are not conductive, so that such contacts can be used with advantage in low-voltage switching devices. However, they cannot be produced in the melting path, but only by powder metallurgy by pressing and sintering a metal powder mixture and are therefore more expensive than contacts made from fine-grain silver.
• silver-tin oxide alloys are also known among these silver alloys and used with great success, in particular for switching direct currents. Because of their high brittleness, these materials are able to compensate for the shrinkage stresses caused by the effects of arcing in the contact surface in the event of thermal or electrical overload. As a result, very good erosion resistance is achieved, especially with heavy-duty circuits.
• silver-nickel alloys with a low nickel content have a low contact resistance, but have a high tendency to sweat, while such alloys have high nickel content has a low tendency to sweat, but has a relatively high contact resistance.
• Silver alloys with tin oxide have a low tendency to weld and are practically weld-resistant at higher tin oxide proportions, but are subject to a relatively high contact resistance.
• silver-tin oxide contact materials Another disadvantage of using silver-tin oxide contact materials is that this material can only be used to a limited extent in the case of miniaturized contacts due to the natural hardness. Wire riveted contacts made of these materials repeatedly lead to manufacturing difficulties due to their difficult cold forming.
• the aim of the invention is therefore to provide a contact material based on silver alloy, which, as mentioned above, combines the advantages of the different materials, is easy to produce and is easy to deform, and also does not have to take polarity into account.
• a silver contact material consisting of the alloy components silver, nickel and tin oxide.
• the invention can be implemented by a silver alloy composed of 90% by weight to 94% by weight of silver, 3% by weight to 5% by weight of nickel and 3% by weight to 5% by weight of tin oxide.
• such an alloy combines the advantages of the two silver alloys discussed above, namely the good manufacturability and processability and the favorable combustion behavior with little material migration, the combustion residues being non-conductive.
• the material is so ductile that thin contact wires can also be easily produced, which can be used for direct riveting into corresponding contact pieces (contact springs).

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Composite Materials (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Contacts (AREA)

Priority Applications (1)

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Publications (1)

Family

ID=8203827

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Cited By (4)

Citations (1)

• 1990
  • 1990-03-28 EP EP90105900A patent/EP0448757A1/fr not_active Withdrawn

Patent Citations (1)

Non-Patent Citations (4)

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