- Steel is one of the most common metal alloys.Jupiterimages/Photos.com/Getty Images
Alloys are metals that are man-made by combining two or more different types of metals. The benefit of alloys is that you can combine metals that have varying characteristics to create an end product that is stronger, more flexible, or otherwise desirable to manufacturers. In other words, alloys take the best characteristics from two or more metals to create a new, better metal.
- One of the most common categories of alloy is steel, which is extremely malleable. Steel is made when iron, coal and limestone are heated and mixed together and then either refined or mixed with even more metals to create a less brittle product, while retaining malleability. Steel can be categorized into three groups; "carbon steel" has limited amounts of carbon, copper, manganese, phosphorus, silicon, and sulfur, while "alloy steel" has higher concentrations of these additive metals and "stainless steel" contains at least 10% chromium.
- Copper is widely used for electricity and thermal conduction, though it is extremely soft in its purest form, so alloys are created to help it retain its shape. Nearly 400 different types of copper alloys are used commercially. One of the oldest types of copper alloys is bronze, which is made by adding tin (in most cases), as well as phosphorus, lead, silicon, nickel, and aluminum in varying concentrations. Also popular is brass, which is made mostly with copper and zinc, but may also contain tin, lead, manganese, and silicon in smaller concentrations. Copper and other metals can either be melted together or cold-worked to mix the metals.
Gold and Platinum Alloys
- In the jewelry industry, gold and platinum are used to create some of the most important alloys. These metals can be easily shaped into fine pieces, making them perfect for jewelry, and other metals are added to create stronger pieces that won't wear down as easily or lose their shape, in addition to giving consumers more affordable options. Yellow gold contains cobalt, copper, silver, and/or zinc, while white gold contains either nickel or palladium, platinum is typically mixed with iridium, ruthenium, or cobalt.
- Pure aluminum is soft, resists corrosion, conducts electricity well, so it is great for products like kitchen foil, but for applications requiring a stronger metal, an aluminum alloy needs to be created. Aluminum alloys are classified based on the other type of metal in the mix (zinc, copper, silicon, manganese, lithium or magnesium) and whether the finished product is wrought, which means it was forged and hammered into shape, or cast, which means it was melted and poured into a shape before cooling.