There are more than 400 copper alloys, each with a unique combination of properties, to suit many applications, manufacturing processes and environments.
Pure copper has the best electrical and thermal conductivity of any commercial metal. Today, over half of the copper produced is used in electrical and electronic applications and this leads to a convenient classification of the types of copper into electrical (high conductivity) and non-electrical (engineering).
Copper forms alloys more freely than most metals and with a wide range of alloying elements to produce the following alloys:
Brass is the generic term for a range of copper-zinc alloys with differing combinations of properties, including strength, machinability, ductility, wear-resistance, hardness, colour, hygienic, electrical and thermal conductivity, and corrosion-resistance.
Bronze alloys are made from copper and tin, and were the first to be developed, about four thousand years ago. They were so important that they led to a period in time being named the Bronze Age.
Gunmetals are alloys of copper with tin, zinc and lead and used for their ease of casting and good strength and corrosion resistance. Containing between 2-11% tin and 1-10% zinc. Modified forms may contain, in addition, such elements as lead (up to 7%) and nickel (up to 6%) when the alloys are classified as ‘leaded gunmetal’ and ‘nickel gunmetal’.
Copper-nickel alloys have excellent resistance to marine corrosion, high thermal conductivity and low susceptibility to attachment of marine macro-oragnisms. The addition of nickel to copper improves strength and corrosion resistance, but good ductility is retained.
Nickel silver alloys are made from copper, nickel and zinc, and can be regarded as special brasses. They have an attractive silvery appearance rather than the typical brassy colour.
Beryllium-copper is the hardest and strongest of any copper alloy, in the fully heat treated and cold worked condition. It is similar in mechanical properties to many high strength alloy steels but, compared to steels, it has better corrosion resistance.
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