Cupronickel

Alloys · Common · Modern

Copper and nickel in whatever proportion is wanted, which buys a silver-white colour that will not tarnish and a hardness copper alone cannot reach. Seawater does not eat it and barnacles will not settle on it, so it lines condenser tubes and the salt water pipework of ships.

Identity

Source
Historical alloy: copper and nickel
Composition
Copper 70-90%, Nickel 10-30%
Over time
The marine grades, 90/10 and 70/30, add about 1 to 2% iron and 1% manganese.
Also known as
Copper-nickel
Ores, before industry and since
Azurite (Copper), Chalcocite (Copper), Chalcopyrite (Copper), Copper (Copper), Malachite (Copper), Tetrahedrite (Copper)
Ores of the industrial age
Bornite (Copper), Chrysocolla (Copper), Covellite (Copper), Cuprite (Copper), Enargite (Copper), Garnierite (Nickel), Limonite (Nickel), Nickeline (Nickel), Pentlandite (Nickel), Skutterudite (Nickel)

Physical Properties

Appearance
Warm silver with a subtle golden-pink tint, maintains its colour without tarnishing
Luster
Metallic
Density
8.9 g/cm³
Melting point
1170 °C
Boiling point
2300 °C
Lighter
Orium
Denser
Nickel
Magnetism
Non-magnetic
Electrical conductivity
Medium

Mechanical Properties

Mohs hardness
3.5
Tensile strength
380 MPa
Softer
Shakudo
Harder
Hepatizon
Workability
Easy
Brittleness
Tough
Malleability
High
Ductility
High

Chemical Properties

Corrosion resistance
Very High
Reactivity
Low

Lore & Narrative

The standard 'silver' coins used in most countries (the UK 5p, the US quarter, the EU 50 cent) are cupronickel. Pure silver was replaced in coinage after World War II when metal shortages made precious-metal coins economically impractical. Most people have handled cupronickel thousands of times without knowing it.

Notable uses
Coinage, marine hardware, heat exchangers, electrical components
Forge uses
Coinage, marine hardware, heat exchangers
Worldbuilding traits
marine, Corrosion-resistant, Common, Coinage

Sources

Browse the Metal Encyclopedia — MGS Toolbox