Aluminum Extrusions

You might not know what aluminum extrusion are, but you've been surrounded by them your entire life. Almost all commercial windows are encased in extruded aluminum housings, the structural components of airliner wings are made from aluminum extrusions, even the Dodge Prowler had a frame made from extruded aluminum. In fact, extrusion is the primary use of raw aluminum followed by casting and machining. As a side note, to give you a perspective on how big the market is, 14% of all the electrical power generated in the United States goes to the processing of aluminum. That's a low of energy.

So how does the process work? It's pretty straight forward really. Round aluminum ingots are heated up to just below the melting point and then pushed through dies shaped like the final product. Hollow shapes are introduced in the dies by means of torpedoes (floating elements in the die) that the aluminum flows around. The aluminum comes out and is straightened, and cut to length. Depending on the specifications required, the aluminum cools and hardens at room temperature or is put in an oven for more accurate tempering.

Hardening. Extruded aluminum can be hardened quenching and age hardening. Quenching simply involves the rapid cooling of extruded material, whereas age hardening can involve simply cooling at room temperature (extruded aluminum will naturally age harden reaching it's maximum strength in a week or so after extrusion) or holding at an elevated temperature for a period of time followed by rapid cooling.