Silver-Nickel Contact Materials
Silver-nickel contact materials are used typically in low and medium power applications. Switches, mini-relays and low power contactors are typical applications for silver-nickel. There is some use of silver-nickel in AC circuit breakers. Contact resistances are relatively low and remain stable over time when compared to silver-copper alloys. As the nickel content increases, the contact resistance increases. The increase in the nickel content also improves the materials resistance to arc erosion. One disadvantage of silver-nickel is its diminishing arc erosion properties over 100 amps.
Silver-nickels are produced through powder metallurgy processes. Compositions for these materials range from 5% nickel to 30% nickel. The lower concentrations of nickel can be manufactured into strip and wire products for further fabrication into contact rivets, clad products and discrete contacts. The materials with the higher nickel concentrations are produced as discrete contacts, through unit compaction processes. The discrete contacts are often supplied with braze alloy flushed to the brazing face.