Copper Alloys Nickel Silver C75700 – Austral Wright Metals
Product Data Sheet – Copper Alloys
Copper Alloys Nickel Silver 12% Nickel Silver UNS-C75700
Also known as Nickel Silver 65-12
Equivalent Alloy Specifications
Australian Product Specifications
AS1566 Rolled Flat Products
Copper Alloys Nickel Silver C75700
Available Forms Austral Wright Metals can supply this alloy as coil or sheet. See the Austral Wright Metals Product Catalogue for standard stock sizes.
General Description 12% nickel silver takes a brilliant polish and has good resistance to corrosion in rural, industrial and marine atmospheres and in fresh water. Since it has good cold formability and an attractive soft ivory-white colour, it is often used for decorative applications.
The alloy is often silver plated, when it may be stamped EPNS (electro plated nickel silver). Alloy C75700 itself does not contain silver. It takes its name from the similarity of its appearance when polished to silver, although it does not have the corrosion resistance of the latter.
C75700 is a copper nickel zinc alloy. The crystal structure is the face centred cubic alpha phase, and hence the alloy has a good combination of strength, hardness and ductility.
Decorative. Holloware, spoons and forks, watch cases, jewellery, medallions, “objets d’art”, pressed, spun or deep drawn items, usually silver plated.
Phase Diagram of C75700
Isothermal Section at 20°C
C75700 has good corrosion resistance to weathering. It is frequently used in decorative applications, where it undergoes little tarnishing in service. If atmospheric corrosion does occur after prolonged exposure without cleaning in an aggressive marine environment, the corrosion products are likely to be green to brown in colour. Exposure tests 25 metres from a surf beach have indicated a likely thickness loss due to corrosion of about 1 mm per year
C75700 should not be used in contact with ammonia or ammonia compounds, as it may suffer stress corrosion cracking. Beware of corrosion inhibitors in piping systems containing carbon steels, which should be checked for compatibility with alloy C75700.
Please consult Austral Wright Metals for advice on your specific application.