Copper Nickel 90/10

Copper Nickel 90/10

Copper Nickel 90/10 is the finest alloy with 90% copper and 10% nickel that also has minor but significant contents of iron and manganese to improve overall strength corrosion resistance. Copper nickel alloy is generally known for its better resistance to corrosion, excellent machinability, and extra-ordinary thermal and electrical conductivity.

Copper nickel 90 10 is face-centered cubic (FCC) structure and isomorphous, which suggests that there is limitless solid solubility of Cu dissolved in Ni or vice versa. Such alloys have high ductility and strength, making them an essential grade of alloys for marine, architectural, and industrial applications.

Physical properties of cupro nickel 90 10
Grade Density (g/cm3) Melting Range °C Elastic Modulus (GPa) Co-eff of Thermal Expansion
(μm/m/°C)
Thermal Conductivity (W/m.K) Specific Heat
(J/Kg.K)
Electrical Resistivity (μΩ.cm)
Cu-Ni 90/10 8.94 1100-1145 140 10-300°C at 100°C 0-100°C 19
17 40 377
Fabrication and heat treatment

Copper nickel alloy can be worked upon with both hot and cold working processes and may be used for the forming of wrought materials which further can be brought into various shapes, though cold working is generally preferred. Hot working temperature range for copper nickel alloy material ranges from 800°C to 900 °C. 

UNS C70600 or just 90 10 as commonly referred as is annealed at temperatures between 593°C and 816°C (1100°F and 1500°F). Copper nickel alloy has good strength at moderately elevated temperatures and can be welded easily.

UNS C70600 chemical composition
GRADE Cu Ni Fe Mn Pb Zn
Cu-Ni 90/10 Min REMAINDER 9 1
Max 11 1.8 1 0.05 1
The corrosion resistance of copper nickel alloy

Copper nickel alloy is a copper-based alloy developed as a cost-efficient substitute for copper nickel 70/30. An addition of around 1.4% iron was introduced to increase its resistance to general corrosion, erosion, and impingement corrosion which may occur due to the turbulent flow of water with air bubbles and silt flowing at high speeds.

The copper nickel 90 10 alloy has small but important levels of iron as a result to create the best combination of resistance to flowing seawater and localized corrosion. Copper nickel alloy has good resistance to chloride pitting and crevice corrosion.

Cupro nickel 90 10 is highly resistant to stress corrosion cracking due to ammonia and sulfide ions and also to biofouling resulting from the release of copper ions. This alloy also has good resistance to pitting and crevice corrosion in still seawater.

90/10 alloy offers steel workers with excellent resistance to stress corrosion, erosion, and biofouling in seawater and brackish water. It is also a good option for excellent fabrication and welding properties, high resistance to hydrogen embrittlement and the retention of mechanical properties down to cryogenic temperature.

Applications of 90 10 copper nickel alloy

Copper nickel 90 10 has undergone rigorous tests that provide a result with excellent antimicrobial properties. It can kill 99.9% of organisms within two hours, including MRSA, influenza A (H1N1), E.coli, and clostridium difficile. This is why copper nickel 90 10 is in high demand for the alloy in application areas such as hygienic and sanitary environments in healthcare units, kitchens, nursing homes and other relevant environments.

For better understanding, here are specifications of copper nickel 90 10 alloy
GRADE UNS OLD BRITISH Din ASTM
Cu-Ni 90/10 C70600 BS EN CuNi30Mn1FE B467, B466, B543, B122, B 171, B 151
CN102 CW352H

One of the major applications of copper nickel 90 10 is marine industries where it proves its good electrical and thermal conductivities as well as corrosion resistance with ease of fabrication of various equipment. The copper nickel alloy 90 10 is a material of selection for condensers and heat exchangers where seawater is utilized as a coolant especially in desalination plants.

Cupro nickel 90 10 is also widely used in: 
  • Offshore platform seawater piping
  • Tidewater power plants
  • Desalination plants
  • Oil refineries, and in the chemical process industry. 
Product applications of copper nickel alloy 90 10 are:
  • Condenser tubes and plates
  • Distiller tubes
  • Tube sheets and baffles for condensers
  • Heat exchangers
  • Evaporator and heat exchanger tubes
  • Saltwater piping
  • Water boxes
  • Ship hulls
  • Hot water tanks.