UNS C18600 Chromium Copper
C18600 copper is a lightly alloyed grade of copper, formulated for primary forming into wrought products. It has a moderately high embodied energy among wrought coppers. In addition, it can have a moderately high tensile strength and a moderately low ductility.
The properties of C18600 copper include two common variations. This page shows summary ranges across both of them. For more specific values, follow the links immediately below. The graph bars on the material properties cards further below compare C18600 copper to: wrought coppers (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
120 GPa 17 x 106 psi
Elongation at Break
8.0 to 11 %
Poisson's Ratio
0.34
Shear Modulus
44 GPa 6.3 x 106 psi
Shear Strength
310 to 340 MPa 45 to 49 x 103 psi
Tensile Strength: Ultimate (UTS)
520 to 580 MPa 76 to 84 x 103 psi
Tensile Strength: Yield (Proof)
500 to 520 MPa 72 to 76 x 103 psi
Thermal Properties
Latent Heat of Fusion
210 J/g
Maximum Temperature: Mechanical
200 °C 390 °F
Melting Completion (Liquidus)
1090 °C 2000 °F
Melting Onset (Solidus)
1070 °C 1960 °F
Specific Heat Capacity
390 J/kg-K 0.092 BTU/lb-°F
Thermal Conductivity
280 W/m-K 160 BTU/h-ft-°F
Thermal Expansion
17 µm/m-K
Electrical Properties
Electrical Conductivity: Equal Volume
70 % IACS
Electrical Conductivity: Equal Weight (Specific)
71 % IACS
Otherwise Unclassified Properties
Base Metal Price
31 % relative
Density
8.9 g/cm3 560 lb/ft3
Embodied Carbon
2.9 kg CO2/kg material
Embodied Energy
46 MJ/kg 20 x 103 BTU/lb
Embodied Water
310 L/kg 37 gal/lb
Common Calculations
Resilience: Ultimate (Unit Rupture Work)
44 to 58 MJ/m3
Resilience: Unit (Modulus of Resilience)
1060 to 1180 kJ/m3
Stiffness to Weight: Axial
7.3 points
Stiffness to Weight: Bending
18 points
Strength to Weight: Axial
16 to 18 points
Strength to Weight: Bending
16 to 17 points
Thermal Diffusivity
81 mm2/s
Thermal Shock Resistance
19 to 20 points
Alloy Composition
Among wrought copper alloys, the composition of C18600 copper is notable for including zirconium (Zr) and chromium (Cr). Zirconium is used to increase recrystallization temperature and to permit or facilitate certain forms of heat treatment. Chromium additions permits certain types of heat treatment to improve mechanical strength.
| Cu | 96.5 to 99.55 | |
| Cr | 0.1 to 1.0 | |
| Fe | 0.25 to 0.8 | |
| Ti | 0.050 to 0.5 | |
| Zr | 0.050 to 0.4 | |
| Ni | 0 to 0.25 | |
| Co | 0 to 0.1 | |
| res. | 0 to 0.5 |
All values are % weight. Ranges represent what is permitted under applicable standards.
Followup Questions
Similar Alloys
Further Reading
Properties and Selection: Nonferrous Alloys and Special-Purpose Materials, ASM Handbook vol. 2, ASM International, 1993