Coppertozinc

Copper-to-zinc, in metallurgical terms, refers to the proportion of copper to zinc in a copper-zinc alloy. The most well-known example of this class is brass, a family of alloys where zinc is the primary alloying element. The zinc content influences color, strength, ductility, electrical conductivity, and corrosion resistance.

Varying the copper-to-zinc ratio changes properties in systematic ways. Increasing zinc content generally raises strength and reduces density, while also turning the alloy from a reddish copper color toward the pale yellow of brass. Higher zinc levels can lower electrical conductivity and ductility, and in some environments zinc can be leached, a phenomenon known as dezincification, which weakens the material over time. The machinability of brass also improves with certain zinc additions, making leaded brasses common for threaded components.

Common brass compositions range roughly from 5% to 45% zinc by weight, with the remainder copper. At lower zinc levels, brasses are more ductile and have a reddish tint; at higher zinc levels, the alloy becomes stronger and more yellow. Specialized brasses may include other elements such as tin, aluminum, nickel, or silicon to tailor properties for specific applications. In contrast to bronze (copper with tin), brass is defined primarily by its copper-to-zinc ratio.

Applications of copper-to-zinc alloys span plumbing fittings, architectural hardware, electrical components, musical instruments, and decorative items. Brass is widely recycled, and standards organizations define common compositions to meet performance and compatibility requirements in different industries.