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Desirable Extruded Aluminum

Fast reliable processes that are profitable with high repeatability are a manufacturer’s best friend. Extrusion is one of these processes. Several metals and materials are used in the extrusion process, going as far back as 1797 with Joseph Brahma. The process continued to evolve into the 19th century with Thomas Burr and again in 1894 with Alexander Dick. Since the beginning, three items have been needed in order for the extrusion process to function. Those items are a ram, a billet and a die. In addition, there are a few types of extrusion and temperatures that are advantageous in their own ways. One of the most preferred metals across industries is aluminum. Extruded aluminum is a favorite in this process for a number of reasons.

Aluminum is valuable to this process and industries alike. Aluminum is the 3rd most abundant element on earth and the most abundant metallic element. Aluminum’s physical properties allow it to be malleable, 100% recyclable while still keeping all of its original properties, and have a low melting point; all of these properties reduce cost during production of extruded aluminum. Some common examples of objects produced are heat sinks, frames, tracks, mullions and rails. However, today one of the most important jobs for extruded aluminum is in the construction of new buildings and infrastructure that is more environmentally sustainable. The metal is highly reliable, rust and temperature resistant and has structural integrity that builders seek when looking for proper metals.

Today, the process has been divided into a few methods. The most common form of extrusion is direct extrusion. Here a billet (the aluminum piece) is pushed through the die by the ram. Next, is indirect extrusion, this process is sometimes called backwards extrusion because the billet moves with the container while the die is stationary. In this process less friction is apparent allowing for higher speeds. The final type is hydrostatic extrusion where the billet is surrounded entirely by pressurized liquid, except where the billet and die make contact. Here no friction is created. Aluminum extrusion is able to be conducted at cold, warm and hot temperatures to create the angle, channel, shape or any other product desired. When using different temperatures during aluminum extrusion, cold production is done at or around room temperature; warm is developed below recrystallization temperature and hot is done above recrystallization, for aluminum that is typically between 650-900 degrees Fahrenheit.

Extruded AluminumPhoto Courtesy of Mid-States Aluminum Corp.

Aluminum and the extrusion process work hand in hand when creating quality products. Though many metals and materials are frequently used in these processes not many match the functionality of aluminum products. That is why aluminum is the most commonly used metal. Depending on the product desired cold, warm or hot processes may need to be utilized to have the greatest possible outcome. Luckily, this is not a problem for extruded aluminum! This 18th century metalworking process continues to develop into the modern day. Its simple design allows for quality products to be made and will continue for many centuries to come.