Bronze

Bronze is among the oldest arificially produced alloys. The term bronze age was coinde by archaeologists to characterize the period following the neolithic when weapons and tools began to be constructed of bronze.

It is narrowest definition, bronze is an alloy of copper and tin, with or without small proportions of other elements such as zinc and phosporous. Certain copper base alloys containing more manganese, iron, lead, or zinc than tin are also regarded as bronzes. Even some alloys that contain no tin are considered bronzes in modern usage, including aluminum bronze (copper aluminum) and silicon bronze (copper silicon). Some copper-base alloys that are actually brasses have been given bronze trade names, such as architectural branze (57% copper, 40% zinc, 3% lead) and commercial bronze ( 90% copper, 10% zinc).




Copper tin alloys are important because of their strength, wear resistance, and corrosion-resistance in a saltwater environment. Copper tin bronzes may be categorized readily according to their composition, which affects their machinability. Alloys with up to 8% tin are used mainly for cold worked applications, such as sheets and coins, those with 8% to 12% tin are used mainly for gears and bearings. Bearings are also made largely from the 12% - 20% tin-copper alloys, and belts are the principal product made from copper-tin alloys with from 20% to 25% tin.

See other alloy: Brass