Small amounts of alloying elements are often added to copper to improve certain characteristics of the copper-based alloy. Alloying can increase or reduce the strength, hardness, electrical and thermal conductivity, corrosion resistance, or change the color of a metal. The addition of a substance to improve one property may have unintended effects on other properties of copper.
Copper and its alloys are widely used in deep draw and flat stamped products because they have excellent electrical and thermal performance, good resistance to corrosion, high ductility and relatively low cost.
Brass is an alloy of copper (70%) and zinc (30%). Brass is harder and cheaper than copper. It is corrosion resistant and is used for musical instruments,water taps, fixtures and ornamental objects. Bronze is an alloy of copper (90%) and tin (10%). Bronze is hard, strong and corrosion resistant.
Bronze is used for castings (statues) and bearings. Cupro-nickel is an alloy of copper (70 to 80%) and nickel (20 to 30%). Cupro-nickel is easily shaped, resistant to corrosion and is used to make "silver" coins such as the 5, 10, 20 and 50p piece. "Silver" coins have not contained real silver since 1947.
Copper can also be used to make gold alloys and smart alloys.
A copper alloy is an alloy of primarily copper, mixed with different alloying elements that give rise to an entire range of materials, each of which is designed to maximize a particular characteristic such as strength, ductility, formability, machinability, or electrical conductivity. These alloys are grouped into "families", the names of which have become familiar - coppers, brasses, bronzes, copper-nickels, and nickel-silvers.
- Coppers are made from copper with trace elements
- Brasses are made from copper alloyed primarily with zinc
- Bronzes are made from copper alloyed primarily with tin
- Copper-Nickels are made from copper alloyed primarily with nickel and manganese
- Nickel Silvers are made from copper alloyed primarily with nickel and zinc
Copper is non-magnetic, non-sparking and non-bacterial. Because it is low in the reactivity series, it is slow to corrode. With medium strength and high fatigue resistance, copper and its alloys are primary metals for electrical applications.