A Brief History of Copper and its Many Applications
Author: lawrencehalter | Posted: 23.05.2012Copper and its alloys are some of the most versatile engineering materials in the world. The combination of physical properties like conductivity, strength, resistance to corrosion, malleability, and ductility make copper suitable for a wide range of applications. These properties can be enhanced further if composition variations are applied in its manufacturing process.
Copper is the oldest metal known to man, its use dating back to prehistoric times. Proof of this is the copper pendant that was found in Iraq, which was dated at approximately 8,700 BC. This attests that copper has been mined for as long as 10,000 years ago. By 5,000 BC, copper alloys were being smelted from simple copper oxides.
The first high-strength copper alloy gave its name to an era, the Bronze Age, which directly follows the Copper Age more than 4,000 years ago. Early bronzes composed of copper and tin and the “phosphorus bronzes” extensively used today for conducting electricity are direct descendants of these primitive alloys. Phosphorus bronzes only have conductivity 10% less than that of pure copper though and cannot be regarded as a high conductivity material.
Types of Copper Alloys
Copper alloys contain small amounts of various alloy elements including chromium, zirconium, tin, sulfur, silver, and iron. These elements modify the basic properties of copper, enhancing strength, malleability, creep resistance, or weld-ability. These alloy elements help make copper applicable to conditions that pure copper cannot withstand.
Brass
Brasses are alloys of copper and zinc containing up to 45% zinc, oftentimes added with small amounts of lead for malleability and tin for strength. This is the same kind of copper used to make a copper rod. Brasses are divided into two classes: the alpha alloys, with less than 37% zinc, and the duplex alloys with 37%-45% zinc. Brasses are often used in architecture, radiator cores and tanks, plugs and lamp fittings, electrical terminals, and more.
Bronze
Bronzes are alloys of copper with tin, with portions of phosphorus, silicon, aluminum, nickel, and manganese. These alloys can be formed into bronze rods to achieve high levels of strength combined with good corrosion resistance. Bronzes can also be used for bearings, terminals, architectural fittings, springs, fixtures, and electrical contacts and connectors.
Aside from creating alloys like brass and bronze rod products, other types of copper alloys are copper nickel, which contain a small amount of iron and sometimes chromium or tin, and nickel silvers, which contain 35% to 45% nickel and zinc and sometimes a little bit of lead to improve malleability. If you want to know how copper and other metals are mixed to produce bronze, visit ehow.com/how_8735474_mix-metals-make-bronze.html.
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