Cupronickel

Five-franc piece (Switzerland) with 25% nickel

GDR commemorative coin with 10% nickel

Copper nickel or fachsprachlich correctly copper-nickel alloy castings are cast alloys with copper as the main component ( copper alloys ), and nickel contents of 10, 20 or 30%. A low silicon content is permissible. The alloys are characterized by high corrosion resistance, even against sea water .

Because of their decorative appearance, utensils and ornaments are often made from such alloys.

They are important in coinage, because modern coins are made from a wrought alloy CuNi25, an alloy of the metals copper (Cu) and nickel (Ni).

Copper was already used as a material for coins in antiquity , but pure nickel was not yet available because of its high melting point, even though the raw copper-nickel stone was already known. Silver and gold were used for valuable coins. Copper already takes on a silvery color with a nickel content below 15%. Around 1960–2000, coins made of a copper-nickel alloy largely replaced the silver coins that had been used up until then for higher denominations.

In the case of euro coins , the alloy CuNi25 is used both for the ring of the 2 euro coin and for the core of the 1 euro coin (known as the pill ), which consists of nickel coated on both sides with CuNi25. The Swiss circulation coins from ten centimes to five francs are also made of this alloy.

literature

Foundry lexicon. 17th edition. Schiele & Schön, Berlin 1997, ISBN 3-7949-0606-3 .

Individual evidence

↑ Copper-nickel alloys. German Copper Institute, accessed on August 26, 2020 (detailed description of the properties of copper-nickel alloys).
^ Foundry Lexicon. 17th edition. Schiele & Schön, Berlin 1997, p. there “coin alloy”.
↑ Wolfgang Piersig: Copper metal of antiquity, present, future . Grin, 2011, ISBN 978-3-640-80929-5 ( page 55 in the Google book search).
^ Friedrich von Schrötter, N. Bauer, K. Regling, A. Suhle, R. Vasmer , J. Wilcke: Dictionary of Coin Studies . 1970, ISBN 3-11-001227-8 ( page 458 in the google book search).
^ Flake C. Campbell: Elements of metallurgy and engineering alloys . 2008, ISBN 978-0-87170-867-0 ( page 482 in the Google book search).
^ Peter Pretsch: From the guilder to the euro: 175 years of the Karlsruhe mint . ISBN 978-3-88190-290-8 ( page 33 in the google book search).
↑ The current coins in circulation. Swiss National Bank (SNB), accessed on July 28, 2011 .

[1] Copper-nickel alloys. German Copper Institute, accessed on August 26, 2020 (detailed description of the properties of copper-nickel alloys).

[2] Foundry Lexicon. 17th edition. Schiele & Schön, Berlin 1997, p. there “coin alloy”.

[3] Wolfgang Piersig: Copper metal of antiquity, present, future . Grin, 2011, ISBN 978-3-640-80929-5 ( page 55 in the Google book search).

[4] Friedrich von Schrötter, N. Bauer, K. Regling, A. Suhle, R. Vasmer , J. Wilcke: Dictionary of Coin Studies . 1970, ISBN 3-11-001227-8 ( page 458 in the google book search).

[5] Flake C. Campbell: Elements of metallurgy and engineering alloys . 2008, ISBN 978-0-87170-867-0 ( page 482 in the Google book search).

[buch-6] Peter Pretsch: From the guilder to the euro: 175 years of the Karlsruhe mint . ISBN 978-3-88190-290-8 ( page 33 in the google book search).

[7] The current coins in circulation. Swiss National Bank (SNB), accessed on July 28, 2011 .