Sep 13 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther DesignationsFabrication and Heat Treatment Machinability Welding Hot Working Cold Working Annealing
Introduction
Pure copper has good electrical and thermal conductivity. Alloys can be freely formed by copper than most metals. More than 400 varieties of copper alloys are available. The UNS nickel silver 55-18 copper alloy is available as wire, rod, and flat products.
The following datasheet gives an overview of the UNS C77000 copper alloy.
Chemical Composition
The following table shows the chemical composition of UNS C77000 copper alloy.
| Element |
Content (%) |
| Cu |
55 |
| Zn |
27 |
| Ni |
18 |
Physical Properties
The physical properties of UNS C77000 copper alloy are tabulated below.
| Properties |
Metric |
Imperial |
| Density |
8.70 g/cm3 |
0.314 lb/in³ |
Mechanical Properties
The mechanical properties of the UNS C77000 copper alloy are outlined in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
414-1000 MPa |
60000-145000 psi |
| Yield strength (depending on temper) |
186-621 MPa |
27000-90100 psi |
| Elongation at break (in 50.8 mm) |
40.00% |
40.00% |
| Elastic modulus |
117 GPa |
17000 ksi |
| Poisson’s ratio |
0.34 |
0.34 |
| Machinability (UNS C36000 (free-cutting brass) = 100) |
30 |
30 |
| Shear modulus |
47 GPa |
6820 ksi |
Thermal Properties
The thermal properties of UNS C77000 copper alloy are given in the following table.
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient (@ 20-300°C/68-572°F) |
16.7 µm/m°C |
9.28 µin/in°F |
| Thermal conductivity (@ 20°C/68°F) |
29 W/mK |
201 BTU in/hr.ft.°F |
Other Designations
Other designations that are equivalent to UNS C77000 copper alloy include:
- ASTM B122
- ASTM B151
- QQ W321
- SAE J461
- SAE J463
Fabrication and Heat Treatment
Machinability
The machinability rating of UNS C77000 copper alloy is 30.
Welding
Brazing, soldering, gas shielded arc welding, seam welding, spot welding, butt welding, and oxyacetylene welding techniques are used for welding UNS C77000 copper alloy. Coated metal arc welding method is not suitable for welding this alloy.
Hot Working
UNS C77000 copper alloy has poor hot forming capacity.
Cold Working
UNS C77000 copper alloy has good cold working capacity.
Annealing
UNS C77000 copper alloy can be annealed at 594 to 816°C (1100 to 1500°F).