Aluminum Extrusion 101: A Comprehensive Guide to Its Process

Step 1: Prepare Extrusion Die

The first step is to make a round-shaped die or use an existing one if available. Preheat the die to precisely 450-500ᵒC before initiating the extrusion process. This helps to ensure that the metal passes through evenly and maximizes the die’s longevity. You can load the die into the extrusion press after the preheating procedure.

Step 2: Pre-Heat Aluminum Billet

The next thing is to cut the cylindrical billet from a stretched log of material, then preheat the billet in an oven to 400-500ᵒC. This technique prepares the billet, making it malleable for the operation. It ensures that it is not molten.

Step 3: Move the Billet to the Extrusion Press

Transfer the billet into the press mechanically after preheating it. However, add lubricant to it before filling the billet into the press. In addition, ensure to put a release agent to the extrusion ram. Consequently, this helps to prevent the billet and ram from joining together.

At this point, the malleable billet is ready in the extrusion press. Here, the hydraulic ram can apply precisely 15,000 tons of pressure. This pressure forces the malleable billet into the container. The aluminum material stretches till it fills the container’s walls.

Step 4: Press-up Extruded Material Against the Die

The aluminum material that fills the container’s walls gets pressed against the extrusion die. You need to apply pressure to the material continuously. Hence, the extruded material emerges through the die opening fully formed.

Step 5: Quench the Extrusion

A puller grasps the extrusion, holding it in place after exiting the press. It safeguards the extrusion as it leaves the press while the alloy undergoes a “quenching” process as it moves along the table. The profile cools off evenly with a full water bath or fan.

Step 6: Shear the Extrusion to the Table Length

Once the aluminum extrusion makes the total table length, use a hot saw to shear it. However, note that temperature is essential at each step of the extrusion method. Despite the quenching process, the extrusion is not always fully cooled off yet.

Step 7: Cool Extrusion to Room Temperature

After completing the shearing process, move the extrusions to a cooling plain from the runout table. The profiles remain there till they achieve room temperature. As soon as they reach room temperature, stretching begins.

Step 8: Transfer Extrusions to the Stretcher and Stretch Them into Alignment

At this stage, you will discover certain twists in the shape of the extruded aluminum that needs correcting. It would help if you had a stretcher to repair these twists. Hold each profile manually at different ends while pulling them till they are entirely straight. This procedure helps to adjust the extrusion to the desired specification.

Step 9: Transfer Extrusion to the Finish to the Finish Saw and Cut Them to Length

At this stage, when the extrusions are fully straightened and work hardened, you can now move them to the saw table. The next thing is for you to cut the extrusions into desired lengths. These lengths are usually between 8-21 feet. Move these extrusions to the oven for aging to the proper temper (T6 or T5) after completing the sawing process.

Step 10: Carry Out Secondary Operations (Heat Treatment, Fabrication, & Surface Finishing)

Upon completion of the extrusion process, you can enhance the properties of these profiles by treating them with heat. After the heat treatment, consider fabricating the extrusions if there are dimensions that need correction. In addition, adding surface finishes helps to enhance the aesthetic appearance and corrosion resistance properties of the extruded aluminum.