List of copper alloys

Brasses

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 the 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.

• Nordic Gold

Bronzes

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 aluminum. The content of aluminum 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 environments, and have low reactivity to sulfur compounds. Aluminum forms a thin passivation layer on the surface of the metal.
• Bell metal
• Brastil
• French bronze is a bronze typical to France in the later 19th century consisted of 91% copper, 2% tin, 6% zinc, and 1% lead. The term "French bronze" was also used for spelter, an alloy which is mainly zinc, but can be finished to resemble real bronze; its composition was typically 5 parts hematite powder to 8 parts lead oxide, formed into a paste with spirits of wine. Variations in tint could be obtained by varying the proportions. The preparation was applied to the article to be bronzed with a soft brush, then polished with a hard brush after it had dried.
• Phosphor bronze
• Nickel bronzes, e.g. nickel silver and cupronickel
• Speculum metal
• UNS C69100

Precious metal alloys

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

† amount unspecified

High temperature copper alloys

Copper alloys that are resilient at high temperatures and maintain mechanical properties are used in many applications such as heat exchangers, castings, and rocket engines. Copper alloys typically have very high thermal conductivities compared to other structural alloys which give them an advantage when large heat fluxes are involved, as they are better at dissipating heat. But copper’s melting point is 1085 Celsius, which is lower than most structural alloys. Therefore, to make use of coppers excellent thermal properties at high temperatures, creep needs to be considered. Creep deformation occurs in materials at relatively high stresses and temperatures. It can dominate as a deformation mechanism in materials above ~0.35 of the melting temperature, so designing against it is critical for high temperature applications. The working temperatures of high temperature copper alloys are up to 700 Celsius. Most of the leading high temperature copper alloys rely on oxide dispersion strengthening (ODS) or precipitation hardening (PH). Some alloys use different methods however, such as alloy, GRCop-84, which takes advantage of intermetallic compounds that form, in its microstructure. These precipitates pin the grains and inhibit grain boundary sliding. The advantage of ODS strengthening is that the oxides will not coarsen during temperature aging while PH alloys will, and the strengthening will be lost. In all cases, the goal of the strengthening mechanisms are to slow down creep deformation, and the various mechanisms that contribute to it such as dislocation glide, dislocation glide, and vacancy diffusion. Some examples of how these strengthening mechanisms work are by increasing the activation energy needed for lattice and grain boundary diffusion, introducing a threshold stress needed to climb or shear particles in matrix, or by pinning grains which inhibits grain boundary sliding. Other factors to be considered at high temperature are oxidation and thermomechanical fatigue which may contribute material degradation.