Nov 13 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther DesignationsFabrication and Heat Treatment Machinability Welding Hot Working Cold Working AnnealingApplications
Introduction
Pure copper has good electrical and thermal conductivity. More than 400 varieties of copper alloys are available. UNS C75200 nickel silver 65-18 copper alloy has high corrosion and tarnish-resistance, and good formability.
The following datasheets gives an overview of UNS C75200 copper alloy.
Chemical Composition
The chemical composition of UNS C75200 copper alloy is tabulated below.
| Element |
Content (%) |
| Cu |
65 |
| Zn |
17 |
| Ni |
18 |
Physical Properties
The physical properties of UNS C75200 copper alloy are given in the following table.
| Properties |
Metric |
Imperial |
| Density |
8.73 g/cm³ |
0.315 lb/in³ |
| Melting point |
1070°C |
1960°F |
Mechanical Properties
The mechanical properties of UNS C75200 copper alloy are outlined in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
386-710 MPa |
56000-103000 psi |
| Yield strength (depending on temper) |
172-621 MPa |
24900-90100 psi |
| Elongation at break ( in 76.2 mm) |
45% |
45% |
| Elasticity modulus |
117 GPa |
17000 ksi |
| Poisson's ratio |
0.34 |
0.34 |
| Machinability (UNS C36000 (free-cutting brass) = 100) |
20 |
20 |
| Shear modulus |
47 GPa |
6820 ksi |
Thermal Properties
The thermal properties of UNS C75200 copper alloy are given in the following table:
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient (@ 20-300 °C/680-572°F) |
16.2 µm/m°C |
9.00 µin/in°F |
| Thermal conductivity (@ 20°C/68°F) |
33 W/mK |
229 BTU in/hr.ft².°F |
Other Designations
Other designations that are equivalent to UNS C75200 copper alloy include:
- ASTM B122
- ASTM B151
- ASTM B206
- ASTM B458
- QQ W321
- SAE J461
- SAE J463
Fabrication and Heat Treatment
Machinability
The machinability rating of UNS C75200 copper alloy is 20.
Welding
UNS C75200 copper alloy can be welded using brazing, soldering, gas shielded arc welding, oxyacetylene welding, spot welding, butt welding, and seam welding methods. Coated metal arc welding method is not preferred for this alloy.
Hot Working
UNS C75200 copper alloy has poor hot forming capacity.
Cold Working
UNS C75200 copper alloy has good cold working capacity.
Annealing
Annealing of UNS C75200 copper alloy can be performed at temperatures ranging from 594 to 760°C (1100 to 1400°F).
Applications
UNS C74500 copper alloy is mainly used in the following applications:
- Musical instrument valves and components
- Jewelry
- Slide fasteners
- Optical instrument components
- Fittings for food and dairy equipment
- Screws
- Rivets
- Decorative items