Copper Casting Alloy (UNS C84500) – Composition, Properties and Uses
If you’ve been researching copper alloys for castings, chances are you have come across UNS C84500. It is a popular option due to its many desirable properties, such as excellent machinability, corrosion resistance, and strength. This blog post will provide an overview of this alloy’s composition, mechanical properties, physical properties, and uses.
UNS C84500 Composition
UNS C84500 is a copper casting alloy composed of 85-89% copper, 8-10% tin, 1.5-3% lead and 0.2-1% zinc. It also contains small amounts of iron and other trace elements that contribute to its overall characteristics.
| Element | Content (%) |
|---|---|
| Copper, Cu | 78 |
| Tin, Sn | 3 |
| Lead, Pb | 7 |
| Zinc, Zn | 12 |
UNS C84500 Mechanical Properties
The mechanical properties of UNS C84500 depend on the exact composition but typically range from 55-72 ksi (380-500 MPa) tensile strength and 20-40 ksi (140-280 MPa) yield strength. This alloy has a high elongation of more than 25%, meaning it can easily be formed into intricate shapes without cracking or breaking. The hardness can range from Rockwell B50 to B80, depending on the heat treatment used during processing.
| Properties | Metric | Imperial |
|---|---|---|
| Hardness, Brinell (500 kg) | 55 | 55 |
| Tensile strength (as cast) | 241 MPa | 35000 psi |
| Yield strength (as cast) | 97.0 MPa | 14100 psi |
| Elongation at break (as cast) | 28.00% | 28.00% |
| Machinability (UNS C36000 (free-cutting brass) = 100) | 90 | 90 |
| Poisson’s ratio | 0.34 | 0.34 |
| Elastic modulus | 117 GPa | 16969 ksi |
UNS C84500 Physical Properties
UNS C84500 has a density of approximately 0.25 lbs/in3 (7 g/cm3). Its melting point is around 1500°F (815°C), so it should not be exposed to temperatures above this threshold to maintain its integrity and performance capabilities over time. The thermal conductivity varies depending on the exact composition but usually falls between 50-70 BTU/hr/ft2/°F (715 – 1000 W/mK).
| Properties | Metric | Imperial |
|---|---|---|
| Density | 8.85 g/cm3 | 0.320 lb/in3 |
UNS C84500 Uses
UNS C84500 is commonly used in applications such as pumps, valves, fasteners and various types of machinery components where good corrosion resistance, machining capabilities and good tensile strength are required. It is also used for decorative items such as door knockers due to its attractive appearance when polished or buffed.
Conclusion
Copper casting alloy UNS C84500 has become increasingly popular due to its excellent machinability, corrosion resistance and strength, and attractive appearance when polished or buffed after casting. Although its use is primarily limited to non-critical applications where structural integrity isn’t critical, it can still be found in numerous products ranging from valves and pumps to decorative items like door knockers, thanks to these desirable characteristics. Understanding this alloy’s composition, mechanical properties, physical properties and uses can help you decide if it’s right for your application or project needs!
Sakshee is a talented blogger, with a particular focus on the Business and Metal Industry. She is passionate about sharing her insights on various metal products and helping professionals to make a better decisions.
