UNS C71520 (ERCuNi) Copper-Nickel
C71520 copper-nickel is a copper-nickel alloy formulated for primary forming into wrought products. ERCuNi is the AWS designation for this material. C71520 is the UNS number.
It can have the highest ductility among wrought copper-nickels. In addition, it has a moderately high base cost and a moderately high embodied energy.
The properties of C71520 copper-nickel include five common variations. This page shows summary ranges across all of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C71520 copper-nickel to: wrought copper-nickels (top), all copper alloys (middle), and the entire database (bottom). A full bar means this is the highest value in the relevant set. A half-full bar means it's 50% of the highest, and so on.
Mechanical Properties
Elastic (Young's, Tensile) Modulus
140 GPa 20 x 106 psi
Elongation at Break
10 to 45 %
Poisson's Ratio
0.33
Rockwell B Hardness
35 to 86
Shear Modulus
51 GPa 7.5 x 106 psi
Shear Strength
250 to 340 MPa 36 to 50 x 103 psi
Tensile Strength: Ultimate (UTS)
370 to 570 MPa 54 to 83 x 103 psi
Tensile Strength: Yield (Proof)
140 to 430 MPa 20 to 63 x 103 psi
Thermal Properties
Latent Heat of Fusion
230 J/g
Maximum Temperature: Mechanical
260 °C 500 °F
Melting Completion (Liquidus)
1170 °C 2150 °F
Melting Onset (Solidus)
1120 °C 2040 °F
Specific Heat Capacity
400 J/kg-K 0.1 BTU/lb-°F
Thermal Conductivity
32 W/m-K 19 BTU/h-ft-°F
Thermal Expansion
15 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
5.7 % IACS
Electrical Conductivity: Equal Weight (Specific)
5.8 % IACS
Otherwise Unclassified Properties
Base Metal Price
40 % relative
Density
8.9 g/cm3 560 lb/ft3
Embodied Carbon
5.0 kg CO2/kg material
Embodied Energy
73 MJ/kg 31 x 103 BTU/lb
Embodied Water
280 L/kg 34 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
54 to 130 MJ/m3
Resilience: Unit (Modulus of Resilience)
67 to 680 kJ/m3
Stiffness to Weight: Axial
8.6 points
Stiffness to Weight: Bending
19 points
Strength to Weight: Axial
12 to 18 points
Strength to Weight: Bending
13 to 17 points
Thermal Diffusivity
8.9 mm2/s
Thermal Shock Resistance
12 to 19 points
Alloy Composition
Among wrought copper alloys, the composition of C71520 copper-nickel is notable for including sulfur (S). Sulfur is used to improve machinability at the cost of a decrease in electrical conductivity.
| Cu | 65 to 71.6 | |
| Ni | 28 to 33 | |
| Fe | 0.4 to 1.0 | |
| Mn | 0 to 1.0 | |
| Zn | 0 to 0.5 | |
| P | 0 to 0.2 | |
| C | 0 to 0.050 | |
| S | 0 to 0.020 | |
| Pb | 0 to 0.020 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
ASTM B151: Standard Specification for Copper-Nickel-Zinc Alloy (Nickel Silver) and Copper-Nickel Rod and Bar
ASTM B122: Standard Specification for Copper-Nickel-Tin Alloy, Copper-Nickel-Zinc Alloy (Nickel Silver), and Copper-Nickel Alloy Plate, Sheet, Strip, and Rolled Bar
ASTM B124: Standard Specification for Copper and Copper Alloy Forging Rod, Bar, and Shapes
ASTM B283: Standard Specification for Copper and Copper-Alloy Die Forgings (Hot-Pressed)
ASM Specialty Handbook: Copper and Copper Alloys, J. R. Davis (editor), 2001