Dr. Dmitri Kopeliovich

According to the Unified Numbering System (UNS):

Copper-Nickel Alloys (Copper-Nickels, Cupro-nickels) are copper alloys, containing 1.5-45% of nickel (Ni) as the major alloying element. Wrought Copper-Nickel alloys are designated with the numbers from C70000 through C73499.

Wrought Copper-Nickel alloys may contain up to 8% of tin (Sn), up to 4.5% of manganese (Mn), up to 2% of iron (Fe), up to 2.5% of chromium (Cr) and up to 1% of silicon (Si) as additional alloying elements.

Copper-nickel-zinc alloys form a separate group called nickel silvers.

Copper-Nickel-Zinc Alloys (Nickel Silvers) are copper alloys containing 8-25% of nickel (Ni) and 17-45% of zinc (Zn) as the major alloying elements. Wrought Copper-Nickel-Zinc alloys are designated with the numbers from C73500 through C79999.

Wrought Copper-Nickel-Zinc alloys may contain up to 6% of manganese (Mn) as additional alloying element.

Copper-Nickel alloys and most of Copper-Nickel-Zinc alloys have mono-phase structure (α-phase) and possess very good formability in cold and hot states.

Wrought Copper-Nickel alloys have moderate mechanical strength and high ductility combined with very good corrosion resistance (particularly in sea water).

Iron, manganese and chromium are added to the wrought Copper-Nickel alloys for increasing their hardness and strength.

The alloys are strengthened by cold work (strain hardening). Ductility of the alloys decreases as a result of cold work.

Separate group of copper-nickel alloys is Spinodal Bronzes: copper-nickel-tin alloys possessing high mechanical strength due to a controlled heat treatment called Spinodal decomposition.

Copper-Nickel alloys are used for manufacturing coins, sea water equipment, evaporators, heat exchanger tubes, automotive hydraulic and cooling systems.

Copper-Nickel alloys (Nickel Silvers) are used in decorative applications and for manufacturing resistance wire, optical parts, screws, rivets, clips, tableware, electrical contacts.

(Materials Data)

• Wrought copper alloy C70400 (Copper-Nickel 5%)
• Wrought copper alloy C70600 (Copper-Nickel 10%)
• Wrought copper alloy C71000 (Copper-Nickel 20%)
• Wrought copper alloy C71500 (Copper-Nickel 30%)
• Wrought copper alloy C74500 (Nickel Silver 65-10)
• Wrought copper alloy C75200 (Nickel Silver 65-18)
• Wrought copper alloy C75400 (Nickel Silver 65-15)
• Wrought copper alloy C75700 (Nickel Silver 65-12)
• Wrought copper alloy C77000 (Nickel Silver 55-18)

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• Wrought Coppers and high copper alloys
• Wrought brasses
• Wrought phosphor bronzes
• Wrought aluminum bronzes
• Wrought silicon bronzes
• Spinodal Bronzes
• Cast copper-nickel alloys and Nickel Silvers
• Classification of copper alloys
• Temper designation of copper alloys
• Treatment of molten copper alloys

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