Copper alloys

Copper alloys are alloys with copper as their principal component. They have high resistance to corrosion.

Due to its high electric conductivity, pure electrolytic copper is used mostly for making of electrical cables.

## Contents

* 1 Compositions
* 1.1 Some common Copper alloys[1]
* 2 Brasses
* 3 Bronzes
* 4 Precious metal alloys
* 5 See also
* 6 References
* 7 External links

## Compositions

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The similarity in external appearance of the various alloys, along with the different combinations of elements used when making each alloy, can lead to confusion when categorizing the different compositions. There are as many as 400 different copper and copper-alloy compositions loosely grouped into the categories: copper, high copper alloy, brasses, bronzes, copper nickels, copper-nickel-zinc (nickel silver), leaded copper, and special alloys. The following table lists the principal alloying element for four of the more common types, along with the name for each type.

Classification of copper and its alloys  Family | Principal alloying element | UNS numbers

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Copper alloys, brass | Zinc (Zn) | C1xxxx-C4xxxx,C66400-C69800
Phosphor bronzes | Tin (Sn) | C5xxxx
Aluminium bronzes | Aluminium (Al) | C60600-C64200
Silicon bronzes | Silicon (Si) | C64700-C66100
Copper nickel, nickel silvers | Nickel (Ni) | C7xxxx

### Some common Copper alloys[1]

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Name  | Nominal composition[2] | Form and condition  | Yield strength[3] | Tensile strength[4] | Elongation[5] | Hardness[6] | Comments

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Copper (ASTM B1, B2, B3, B152, B124, R133)  | Cu 99.9  | Annealed  | 10  | 32  | 45  | 42  | Electrical equipment, roofing, screens
" | " | Cold-drawn  | 40  | 45  | 15  | 90  | "
" | " | Cold-rolled  | 40  | 46  | 5  | 100  | "
Gilding metal (ASTM B36)  | Cu 95.0, Zn 5.0  | Cold-rolled  | 50  | 56  | 5  | 114  | Coins, ammunition casings
Cartridge brass (ASTM B14, B19, B36, B134, B135)  | Cu 70.0, Zn 30.0  | Cold-rolled  | 63  | 76  | 8  | 155  | Good for cold-working; radiators, hardware, electrical
Phosphor bronze (ASTM B103, B139, B159)  | Cu 70.0, Sn 10.0, P 0.25  | Spring temper  | —  | 122  | 4  | 241  | High fatigue-strength and spring qualities
Yellow or High brass (ASTM B36, B134, B135)  | Cu 65.0, Zn 35.0  | Annealed  | 18  | 48  | 60  | 55  | Good corrosion resistance
" | " | Cold-drawn  | 55  | 70  | 15  | 115  | "
" | " | Cold-rolled (HT)  | 60  | 74  | 10  | 180  | "
Manganese bronze (ASTM 138)  | Cu 58.5, Zn 39.2, Fe 1.0, Sn 1.0, Mn 0.3  | Annealed  | 30  | 60  | 30  | 95  | Forgings
" | " | Cold-drawn  | 50  | 80  | 20  | 180  | "
Naval brass (ASTM B21)  | Cu 60.0, Zn 39.25, Sn 0.75  | Annealed  | 22  | 56  | 40  | 90  | Resistance to salt corrosion
" | " | Cold-drawn  | 40  | 65  | 35  | 150  | "
Muntz metal (ASTM B111)  | Cu 60.0, Zn 40.0  | Annealed  | 20  | 54  | 45  | 80  | Condensor tubes
Aluminium bronze (ASTM B169 alloy A, B124, B150)  | Cu 92.0, Al 8.0  | Annealed  | 25  | 70  | 60  | 80  | —
" | " | Hard  | 65  | 105  | 7  | 210  | "
Beryllium copper (ASTM B194, B196, B197)  | Cu 97.75, Be 2.0, Co or Ni 0.25  | Annealed, solution-treated  | 32  | 70  | 45  | B60 (Rockwell)  | Electrical, valves, pumps
" | " | Cold-rolled  | 104  | 110  | 5  | B81 (Rockwell)  | "
Free-cutting brass  | Cu 62.0, Zn 35.5, Pb 2.5  | Cold-drawn  | 44  | 70  | 18  | B80 (Rockwell)  | Screws, nuts, gears, keys
Nickel silver (ASTM B112)  | Cu 65.0, Zn 17.0, Ni 18.0  | Annealed  | 25  | 58  | 40  | 70  | Hardware
" | " | Cold-rolled  | 70  | 85  | 4  | 170  | "
Nickel silver (ASTM B149)  | Cu 76.5, Ni 12.5, Pb 9.0, Sn 2.0  | Cast  | 18  | 35  | 15  | 55  | Easy to machine; ornaments, plumbing
Cupronickel (ASTM B111, B171)  | Cu 88.35, Ni 10.0, Fe 1.25, Mn 0.4  | Annealed  | 22  | 44  | 45  | –  | Condensor, salt-water pipes
" | " | Cold-drawn tube  | 57  | 60  | 15  | –  | "
Cupronickel  | Cu 70.0, Ni 30.0  | Wrought  | –  | –  | –  | –  | Heat-exchange equipment, valves
Red brass (ASTM B30 4A)  | Cu 85.0, Zn 5.0, Pb 5.0, Sn 5.0  | Cast  | 17  | 35  | 25  | 60  | —

1. ↑ Lyons, William C. and Plisga, Gary J. (eds.) Standard Handbook of Petroleum & Natural Gas Engineering, Elsevier, 2006
2. ↑ percent
3. ↑ 0.2% offset, 1000 lb /in²
4. ↑ 1000 lb /in²
5. ↑ in 2 inches, percent
6. ↑ Brinell scale

## Brasses

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Main article: Brass

A brass is an alloy of copper with zinc. Brasses are usually yellow in color. The zinc content can vary between few % to about 40%; as long as it is kept under 15%, it does not markedly decrease corrosion resistance of copper.

Brasses can be sensitive to selective leaching corrosion under certain conditions, when zinc is leached from the alloy (dezincification), leaving behind a spongy copper structure.

## Bronzes

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Main article: Bronze

A bronze is an alloy of copper and other metals, most often tin, but also aluminium and silicon.

* Aluminium bronzes are alloys of copper and aluminium. The content of aluminium ranges mostly between 5-11%. Iron, nickel, manganese and silicon are sometimes added. They have higher strength and corrosion resistance than other bronzes, especially in marine environment, and have low reactivity to sulfur compounds. Aluminium forms a thin passivation layer on the surface of the metal.

* Phosphor bronze

* Nickel bronzes, e.g. nickel silver and cupronickel

## Precious metal alloys

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Copper is often alloyed with precious metals like silver and gold, to create, for example, Corinthian bronze, hepatizon, tumbaga and shakudo.

## See also

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* Copper clad steel

## References

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* Machinery's Handbook, Industrial Press Inc, New York, ISBN 0-8311-2492-X, Edition 24, page 501

## External links

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* National Pollutant Inventory - Copper and compounds fact sheet
* The Dutch Brass Alloys Manufacturer

nl:Koperlegering