How it Works: The Aluminum Extrusion Process
Aluminum extrusion is a versatile, heat-dependent process used to shape aluminum alloys into unique cross-sectional profiles. T-slot aluminum and aluminum angles are two of the most common aluminum profiles produced, but custom dies can be created for unique applications.
Selecting the Right Aluminum Alloy for Extrusion
Formability and workability, weldability, machining capabilities, corrosion resistance, heat treatability, material strength, and end-use applications must all be taken into account when choosing which type of aluminum alloy to use for extrusion.
How to Extrude Aluminum
Some of the basic steps in the aluminum extrusion process are outlined below:
Extrusion log
The extrusion log is an alloy cylinder up to 72 inches long, which serves as the raw material for extrusion.
Preheating
The logs are loaded into a furnace and heated to 900 °F. This is hot enough to soften the aluminum alloy but not cause it to lose its cylindrical shape.
Extrusion process
The extrusion log is then loaded into the extruder machine, where a hydraulic ram forces the log through a shaped opening in a die.
Quenching
The log is immediately cooled using water, allowing the operators to precisely control the rate of cooling.
Stretching, Cutting, and Aging
The extrusions are then stretched to correct any shape deformities. The extrusions are then cut to a determined length and aged in an oven to reach the desired hardness.
Aluminum Surface Finishing
The pieces can then be run through a finishing machine to debur the extrusions, soften any sharp edges, and provide a surface ready for coating.
