List of copper alloys

Metal alloy with copper as its principal component

Example of a copper alloy object: a Neo-Sumerian "Foundation Nail" of Gudea, circa 2100 BC, made in the lost-wax cast method, overall: 17.5 x 4.5 x 7.3 cm, probably from modern-day Iraq, now in the Cleveland Museum of Art (Cleveland, Ohio, USA)

Copper alloys are metal alloys that have copper as their principal component. They have high resistance against corrosion. The best known traditional types are bronze, where tin is a significant addition, and brass, using zinc instead. Both of these are imprecise terms, having both been commonly referred to as lattens in the past. Today the term copper alloy tends to be substituted, especially by museums.[1]

Composition

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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 used in modern industry, along with the name for each type. Historical types, such as those that characterize the Bronze Age, are vaguer as the mixtures were generally variable.

Classification of copper and its alloys Family Principal alloying element UNS numbers Copper alloys, brass Zinc (Zn) C1xxxx–C4xxxx,C66400–C69800 Phosphor bronze Tin (Sn) C5xxxx Aluminium bronzes Aluminium (Al) C60600–C64200 Silicon bronzes Silicon (Si) C64700–C66100 Cupronickel, nickel silvers Nickel (Ni) C7xxxx Binary Cu Si phase diagram, the base phase diagram for silicon bronzes Binary Cu Al phase diagram, the base phase diagram for aluminium bronzes, generated using NIMS Open databases https://cpddb.nims.go.jp/cpddb/al-elem/alcu/alcu.htm - DOI https://doi.org/10.48505/nims.3060 and Computherm Pandat https://computherm.com/ Binary Cu Sn phase diagram, the base phase diagram for bronzes, generated using NIMS Open databases https://cpddb.nims.go.jp/cpddb/cu-elem/cusn/cusn.htm - DOI https://doi.org/10.48505/nims.3060 and Computherm Pandat https://computherm.com/ Binary Cu Zn phase diagram, the base phase diagram for brasses, generated using NIMS Open database https://cpddb.nims.go.jp/cpddb/cu-elem/cu_index.htm  Cu-Zn - DOI https://doi.org/10.48505/nims.3060 and Computherm Pandat https://computherm.com/ Mechanical properties of common copper alloys[2] Name Nominal composition (percentages) Form and condition Yield strength (0.2% offset, ksi) Tensile strength (ksi) Elongation in 2 inches (percent) Hardness (Brinell scale) Comments 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, bullet jackets 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, drawn cartridge cases. Phosphor bronze (ASTM B103, B139, B159) Cu 89.75, 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, oilfield tools, aerospace landing gears, robotic welding, mold making [3] 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 B122) 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 [4] 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 Ounce metal[5] Copper alloy C83600 (also known as "Red brass" or "composition metal") (ASTM B62) Cu 85.0, Zn 5.0, Pb 5.0, Sn 5.0 Cast 17 37 25 60 — Gunmetal (known as "red brass" in US) Varies Cu 80-90%, Zn <5%, Sn ~10%, +other elements@ <1% Mechanical properties of Copper Development Association (CDA) copper alloys[6] Family CDA Tensile strength [ksi] Yield strength [ksi] Elongation (typ.) [%] Hardness
[Brinell 10 mm-500 kg] Machinability [YB = 100] Min. Typ. Min. Typ. Red brass 833 32 10 35 35 35 836 30 37 14 17 30 50–65 84 838 29 35 12 16 25 50–60 90 Semi-red brass 844 29 34 13 15 26 50–60 90 848 25 36 12 14 30 50–60 90 Manganese bronze 862 90 95 45 48 20 170–195† 30 863 110 119 60 83 18 225† 8 865 65 71 25 28 30 130† 26 Tin bronze 903 40 45 18 21 30 60–75 30 905 40 45 18 22 25 75 30 907 35 44 18 22 20 80 20 Leaded tin bronze 922 34 40 16 20 30 60–72 42 923 36 40 16 20 25 60–75 42 926 40 44 18 20 30 65–80 40 927 35 42 21 20 77 45 High-leaded tin bronze 932 30 35 14 18 20 60–70 70 934 25 32 16 20 55–65 70 935 25 32 12 16 30 55–65 70 936 33 30 16 21 15 79-83 80 937 25 35 12 18 20 55–70 80 938 25 30 14 16 18 50–60 80 943 21 27 13 10 42–55 80 Aluminium bronze 952 65 80 25 27 35 110–140† 50 953 65 75 25 27 25 140† 55 954 75 85 30 35 18 140–170† 60 955 90 100 40 44 12 180–200† 50 958 85 95 35 38 25 150-170† 50 Silicon bronze 878 80 83 30 37 29 115 40 † Brinell scale with 3000 kg load Comparison of copper alloy standards[6] Family CDA ASTM SAE SAE superseded Federal Military Red brass 833 836 B145-836 836 40 QQ-C-390 (B5) C-2229 Gr2 838 B145-838 838 QQ-C-390 (B4) Semi-red brass 844 B145-844 QQ-C-390 (B2) 848 B145-848 QQ-C-390 (B1) Manganese bronze 862 B147-862 862 430A QQ-C-390 (C4) C-2229 Gr9 863 B147-863 863 430B QQ-C-390 (C7) C-2229 Gr8 865 B147-865 865 43 QQ-C-390 (C3) C-2229 Gr7 Tin bronze 903 B143-903 903 620 QQ-C-390 (D5) C-2229 Gr1 905 B143-905 905 62 QQ-C-390 (D6) 907 907 65 Leaded tin bronze 922 B143-922 922 622 QQ-C-390 (D4) B-16541 923 B143-923 923 621 QQ-C-390 (D3) C-15345 Gr10 926 926 927 927 63 High-leaded tin bronze 932 B144-932 932 660 QQ-C-390 (E7) C-15345 Gr12 934 QQ-C-390 (E8) C-22229 Gr3 935 B144-935 935 66 QQ-C-390 (E9) 937 B144-937 937 64 QQ-C-390 (E10) 938 B144-938 938 67 QQ-C-390 (E6) 943 B144-943 943 QQ-C-390 (E1) Aluminium bronze 952 B148-952 952 68A QQ-C-390 (G6) C-22229 Gr5 953 B148-953 953 68B QQ-C-390 (G7) 954 B148-954 954 QQ-C-390 (G5) C-15345 Gr13 955 B148-955 955 QQ-C-390 (G3) C-22229 Gr8 958 QQ-C-390 (G8) Silicon bronze 878 B30 878

The following table outlines the chemical composition of various grades of copper alloys.

Chemical composition of copper alloys[6][7] Family CDA AMS UNS Cu [%] Sn [%] Pb [%] Zn [%] Ni [%] Fe [%] Al [%] Other [%] Red brass 833 C83300 93 1.5 1.5 4 C83400[8] 90 10 836 4855B C83600 85 5 5 5 838 C83800 83 4 6 7 Semi-red brass 844 C84400 81 3 7 9 845 C84500 78 3 7 12 848 C84800 76 3 6 15 Manganese bronze C86100[9] 67 0.5 21 3 5 Mn 4 862† C86200 64 26 3 4 Mn 3 863† 4862B C86300 63 25 3 6 Mn 3 865 4860A C86500 58 0.5 39.5 1 1 Mn 0.25 Tin bronze 903 C90300 88 8 4 905 4845D C90500 88 10 0.3 max 2 907 C90700 89 11 0.5 max 0.5 max Leaded tin bronze 922 C92200 88 6 1.5 4.5 923 C92300 87 8 1 max 4 926 4846A C92600 87 10 1 2 927 C92700 88 10 2 0.7 max High-leaded tin bronze 932 C93200 83 7 7 3 934 C93400 84 8 8 0.7 max 935 C93500 85 5 9 1 0.5 max 937 4842A C93700 80 10 10 0.7 max 938 C93800 78 7 15 0.75 max 943 4840A C94300 70 5 25 0.7 max Aluminium bronze 952 C95200 88 3 9 953 C95200 89 1 10 954 4870B
4872B C95400 85 4 11 C95410[10] 85 4 11 Ni 2 955 C95500 81 4 4 11 C95600[11] 91 7 Si 2 C95700[12] 75 2 3 8 Mn 12 958 C95800 81 5 4 9 Mn 1 Silicon bronze C87200[13] 89 Si 4 C87400[14] 83 14 Si 3 C87500[15] 82 14 Si 4 C87600[16] 90 5.5 Si 4.5 878 C87800[17] 80 14 Si 4 C87900[18] 65 34 Si 1 † Chemical composition may vary to yield mechanical properties

Brasses

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A brass is an alloy of copper with zinc. Brasses are usually yellow in colour. 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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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% and 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 sulphur compounds. Aluminium forms a thin passivation layer on the surface of the metal.
• Bell metal
• Phosphor bronze
• Nickel bronzes, e.g. nickel silver and cupronickel
• Speculum metal
• UNS C69100

Precious metal alloys

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Copper is often alloyed with precious metals like gold (Au) and silver (Ag).

† amount unspecified

See also

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References

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Bibliography

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• Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L. (1992). Machinery's Handbook (24 ed.). New York: Industrial Press Inc. p. 501. ISBN 0-8311-2492-X.