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The Differences Between Anodized Aluminum & Billet Aluminum

Aluminum is the most abundant element in the earth's crust, but it is never found in its pure form in nature. It took about 100 years from the notion that bauxite contained an unknown element (aluminum) to the perfection of the Bayer method of extracting aluminum from bauxite. Two years later, in 1888, Alcoa was formed as the Pittsburgh Reduction company, and by 1909 41,000 kilograms of aluminum were produced a day. Aluminum is light, plentiful and cost-effective for manufacturing and industry. Two common types of aluminum used in manufacturing are anodized aluminum and billeted aluminum.

Pure Aluminum
- After bauxite is processed, pure aluminum is formed. This is a soft metal that conducts electricity better than almost any substance and does not react to magnets. It is quite reactive and is easily made into alloys with stronger metals. Because of its softness, pure aluminum is not usually useful to industry because of its lack of strength. By taking advantage of its unique chemical properties, industry has created aluminum that takes advantage of its light weight but also has the strength needed for most manufacturing.
Anodized Aluminum
- Anodized aluminum is pure aluminum that has been oxidized. Unlike most metals, the oxidation process strengthens aluminum while still retaining its light weight. Creating anodized aluminum is relatively easy. Pure aluminum is placed into an acid bath, such as acetone. This creates a chemical battery with the aluminum being the positive charge and the acid a negative charge. An electrical current is then run through the bath causing the aluminum to oxidize. This creates a very hard and strong compound called anodized aluminum. The only drawback to this compound is that through oxidation, the aluminum loses its conductivity.
Billeted Aluminum
- Billeted aluminum is simply aluminum or aluminum alloys that have been formed into ingots, bars or rolls by a process called extrusion. Simply put, the metal is placed into a chamber, sufficient heat and pressure are applied, and the metal will conform to the shape of the chamber. Most often, aluminum alloys are created with zinc, copper, magnesium and manganese. These alloys retain the conductivity of aluminum and also its light weight.
Usage of Anodized and Billeted Aluminum
- Anodized aluminum is most often found in high-end cookware. Heat spreads evenly and rapidly through anodized aluminum, and it also has a protective finish due to the toughness of the compound. Other uses are in building exteriors where the framework is exposed to the elements and in satellites that orbit the earth. Billeted aluminum is used in a wide variety of manufacturing. Most everything made of aluminum, such as aluminum foil, cans and consumer products, are created from billeted aluminum alloys.

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