Nov 12 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesMechanical PropertiesThermal PropertiesOther DesignationsFabrication and Heat Treatment Machinability Welding Forging Hot Working Cold Working AnnealingApplications
Introduction
UNS C18700 leaded copper alloys are primary alloys that can be spot welded and seam welded to achieve hardness and electrical conductivity of 96% IACS. These alloys can be heat treated and cold worked. They are suitable for applications, which require high mechanical properties and deformation resistance at high temperature.
The following datasheet will give an overview of UNS C18700 leaded copper alloys.
Chemical Composition
The following table shows the chemical composition of UNS C18700 copper alloys.
| Element |
Content (%) |
| Cu, Copper |
99.0 |
| Pb, Lead |
1.0 |
Physical Properties
The physical properties of UNS C18700 copper alloys are given in the following table.
| Properties |
Metric |
Imperial |
| Density |
8.89 g/cm3 |
0.321 lb/in3 |
| Melting point |
953°C |
1747°F |
Mechanical Properties
The mechanical properties of UNS C18700 copper alloys are tabulated below.
| Properties |
Metric |
Imperial |
| Hardness, Rockwell B (50.8 - 76.2 mm/2.00 - 3.00 in) |
65 |
65 |
| Hardness, Rockwell B (25.4 - 50.8 mm/1.00 - 2.00 in) |
70 |
70 |
| Hardness, Rockwell B (25.4 mm/1.00 in, heat treated) |
75.0 |
75.0 |
| Tensile strength at break (any thickness) |
379 MPa |
55000 psi |
| Yield strength (0.500%, any thickness) |
379 MPa |
55000 psi |
| Modulus of elasticity |
117 GPa |
17000 ksi |
| Poisson's ratio |
0.181 |
0.181 |
| Shear modulus |
49.6 GPa |
7200 ksi |
Thermal Properties
The thermal properties of UNS C18700 copper alloys are tabulated below.
| Properties |
Metric |
Imperial |
| Thermal expansion coefficient (20.0 - 300°C/ 68.0 - 572°F) |
17.6 µm/m°C |
9.78 µin/in°F |
| Thermal conductivity (@20.0°C/ 68.0°F) |
377 W/mK |
2620 BTU in/hr.ft.°F |
Other Designations
Other designations that are equivalent to UNS C18700 copper alloys include:
- ASTM B301
- SAE J461
- SAE J463
Fabrication and Heat Treatment
Machinability
The machinability rate of C18700 copper alloys is 85.
Welding
Welding methods such as soldering, brazing and butt welding are preferred for C18700 copper alloys. Oxyacetylene welding, gas shielded arc welding, coated metal arc welding, seam welding and spot welding are not preferred for this type of alloys.
Forging
C18700 copper alloys are forged at temperatures ranging from 760 to 871°C (1400 to 1600°F).
Hot Working
C18700 copper alloys have poor hot working property.
Cold Working
C18700 copper alloys have good cold working property.
Annealing
Annealing of C18700 copper alloys is performed at temperatures ranging from 427 to 649°C (800 to 1200°F).
Applications
The following are the major applications of UNS C18700 copper alloys:
- Electrical/electronic connectors
- Welding torch tips