Chromium zirconium Alloy C18150 has good thermal and electrical conductivity. More than 400 types of these copper alloys are available, but C18150 is highly preferred since it has high strength and wear resistance at elevated temperatures. C18150 is used extensively for cap-style resistance welding electrodes. It can provide less sticking and resist deformation for much longer than its copper-chrome counterpart in some specific situations.
The chemical composition of C18150 is 1% chromium, 98.85% copper, and 0.15% zirconium. The addition of Zirconium to chromium copper improves creep resistance at high operating temperatures and reduces sticking of electrodes to the work during spot welding of galvanized or coated materials. The physical copper properties of C18150 include a density of 8.89 grams per cubic centimeter.
TYPICAL USES OF CHROMIUM ZIRCONIUM
Chromium zirconium is a unique copper alloy that's able to decrease stress under constant strain. It's typically used with steel bolts in turbine casting, which must be straightened and typed.
Machining includes a variety of processes in which a raw piece of material is cut into a desired final shape and size by a controlled material-removal process. The machinability rating of C18150 is 30% which is moderate. The use of a cutting tool with a chip breaker is recommended.
MATERIAL PROPERTIES OF C18150
The C18150 copper alloy has a combination of properties as below:
- Tensile strength: 220-540 N/mm2
- 0.2% Proof strength: 100-440 N/mm2
- % Elongation: 35-5
- Hardness (HV): 55-175
- Electrical conductivity: 80% IACS
- Thermal conductivity: 300 W/moC (compared to copper 394 W/moC)
The most common fabrication properties of C18150 are bending, cold heading, and machining. The machinability rating of C18150 is 20. The fabrication properties of C18150 Copper can be categorized as either good, not recommended, fair, or excellent. The properties are as follows:
- Good for:
- Gas shielded arc welding
- Excellent for:
- Capacity for being cold worked
- Fair for:
- Not recommended for:
- Oxyacetylene welding
- Coated metal arc welding
- Spot Welding
- Seam Welding