Aug 6 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther DesignationsFabrication and Heat Treatment Cold Working Welding Forging Machinability Hot WorkingApplications
Introduction
Copper alloys are available in more than 400 varieties. Each copper alloy variety has specific properties that suit a number of manufacturing processes, environments and applications. Some of the copper alloy forms include:
- Beryllium copper
- Nickel silver
- Tin bronze
- Brass
- Phosphor bronze
- Gunmetal
- Aluminum bronze
- Copper-nickel
UNS C18400 chromium copper alloys features moderately high elevated strength and conductivity 80% IACS. The datasheet below provides an overview of UNS C18400 chromium copper alloys.
Chemical Composition
The chemical composition of UNS C18400 chromium copper alloys is outlined in the following table.
| Element |
Content (%) |
| Cu |
99.2 |
| Cr |
0.8 |
Physical Properties
The following table shows the physical properties of UNS C18400 chromium copper alloys.
| Properties |
Metric |
Imperial |
| Density |
8.89 g/cc |
0.321 lb/in³ |
| Melting point |
1070.0°C |
1958°F |
Mechanical Properties
The mechanical properties of UNS C18400 chromium copper alloys are displayed in the following table.
| Properties |
Metric |
Imperial |
| Tensile strength |
234-593 MPa |
33900-86000 psi |
| Yield strength (depending on temper) |
97.0-531 MPa |
14100-77000 psi |
| Elongation at break (in 127 mm (2in.)) |
40.00% |
40.00% |
| Machinability (UNS C36000 (free-cutting brass) = 100) |
20 |
20 |
| Shear modulus |
50.0 GPa |
7250 ksi |
| Poisson's ratio |
0.34 |
0.34 |
| Elastic modulus |
117 GPa |
16969 ksi |
Thermal Properties
The thermal properties of UNS C18400 chromium copper alloys are given in the following table.
| Properties |
Metric |
Imperial |
| Thermal expansion co-efficient (@20-100°C/68-212°F) |
17.6 µm/m°C |
9.78 µin/in°F |
| Thermal conductivity (@20°C/68°F) |
171 W/mK |
1190 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to UNS C18400 chromium copper alloys are:
- MIL C-19311
- SAE J461
- SAE J463
Fabrication and Heat Treatment
Cold Working
UNS C18400 alloys can be cold worked in an excellent manner.
Welding
UNS C18400 alloys can be welded using brazing, gas shielded arc welding, butt welding and soldering processes. Welding processes not recommended for these alloys include seam welding, oxyacetylene welding, spot welding and coated metal arc welding.
Forging
UNS C18400 alloys can be hot worked between 760 and 871°C (1400 and 1600°F). The hot forgeability rating of these alloys is 80.
Machinability
The machinability rating of UNS C18400 alloys is 20.
Hot Working
UNS C18400 alloys have good hot forming capacity.
Applications
UNS C18400 alloys are also used in mechanical and electrical power transmission devices, high-strength fasteners for elevated-temperature service and circuit breaker parts. They are also used in welding equipment components that include wheels, tips and clamps.