Brass is a binary alloy; this means that it’s a material made up of two different metals; Copper and Zinc. It is not a new material, it has been produced as early the 5th century BC in China. However, until the 18th century it was not easy to make; zinc was achieved by mixing smithsonite ore (zinc carbonate) with the copper, heating the mixture until the vapour from the zinc permeated the copper. Once the Romans had mastered how to produce brass, the alloy was used for coinage in areas of the empire. Now, the relative ease of production, and Brass’s valuable properties, has made it one of the most widely used alloys.
The properties in Brass will vary depending on the Copper-Zinc ratio, there are up to 60 variations specified by the European Norm Standards. However, most brasses are valued for their work ability, hardness, corrosion resistance and aesthetics. It can be cast and shaped with ease, at a low melting point, while maintaining its strength. The more zinc the better it is for casting, although the less zinc the more malleable and ductile the Brass is, making it good for cold working, welding and brazing. When there is a high copper content, the metal forms a patina on its surface that protects it from further corrosion, a characteristic that is useful when the metal will be exposed to moisture and weathering. The metal has both good heat and electrical conductivity although it can be up to 23% to 44% less conductive than pure copper, and it is wear and spark resistant. Brass ́s bacteriostatic properties have also made it fairly common in healthcare facilities and its acoustics make it particularly interesting for “brass band” musical instruments. Aesthetically, the range of colours it can be produced in, from reds to yellows, have attracted artists and designers for centuries. Brass is also a low friction and non-magnetic alloy.