Answer to Question #325622 in General Chemistry for Hanieh

Question

Hello. I want chemical properties of copper-nickel with the UNS number: 20400 and 10 90 copper-nickel. Are these two close? Is UNS number unique?

Answer 1

There are more than several copper nickel alloys, all with UNS C7XXXX numbers. Nickel content varies from 2 % to 25 % nickel in the common copper-nickel alloys and is used as a corrosion resisatnt material in industry application as well as coinage (UNS C71300) in the US.

C71500, a silvery white alloy, with 30 % nickel is commonly used in sea water applicaitons offering superior corrosion protection. See the CDA data link in trhe footnote for more information on corrosion resistance. C

Some physical proerties of C71500 (70Cu–30Ni) as published by the CDA include :