According to recent reports, the use of materials made from aluminum extrusion has increased exponentially over the last decades. This accelerated growth is not surprising since the material has plenty to offer in today’s manufacturing environment.

In this article, we will look into the aluminum extrusion process. It is simplified into ten easy steps for everybody to understand what it is and how it works.

What is Aluminum Extrusion?

If you are wondering what aluminum extrusion is, just look at how a toothpaste comes out of the tube. In aluminum extrusion, the aluminum alloy is forced through a die that features a specific cross-sectional profile. When the alloy comes out of the die, it will have the same shape as the die.

There are plenty of shapes that can be extruded to this process. You can choose from a solid shape like in rods, hollow like in tubes, and semi-hollow that has a partially enclosed void.

The aluminum extruded materials have many applications across different sectors, including electronics, energy, aerospace, automotive, and many more.

The 10-Step Aluminum Extrusion Process

To better understand the process, here are the steps involved in the extrusion process.

1. Preparation of the die and moving to the extrusion press

The first step in the aluminum extrusion process is the preparation of the die according to the design specs. Before the actual extrusion, this die is preheated between 450 to 500 degrees (Celsius) to ensure an even flow of metal and extend its life. When the desired temperature is achieved, it is brought into the extrusion press.

2. Preheating of the aluminum billet

The next step in the preparation is heating the billet. This is a solid and cylindrical block of alloy material and is preheated in an oven to the same temperature as the die. The heating process makes it malleable but not fluid.

3. Transfer of billet into the extrusion press

Once the billet is heated, it is ready for transfer to the extrusion press. Before transferring it should be coated with a lubricant. The extrusion ram is also lubricated to prevent the billet from sticking into it.

4. Pushing of the billet with the ram

The malleable billet needs pushing to pass through the extrusion press. In this step, 15,000 tons of pressure is applied to the ram to push the billet. This material will expand and fill the container.

5. Actual extrusion of the material

Upon filling the container, the alloy will be pushed into the extrusion die. With continuous pressure, the aluminum alloy will have to push its way out of the die. Once it emerges from the die, it has a fully-formed profile.

6. Quenching

Once the extruded material emerges from the die, it will be transferred to the runout table. Here, the material is quenched or run into a water bath to cool it. In another setup, there are fans above the table for the same purpose.

7. Shearing

When the extruded material has reached the full table length, it is cut with a hot saw to separate them from the extrusion process. This material has not yet fully cooled and has to undergo further processing.

8 Cooling

The next post-production step for the alloy is cooling at room temperature. From the runout table, the material is transferred to a cooling table until they reach room temperature.

9. Stretching

The extrusion process does not stop at cooling. Once the material is cooled, it has to undergo some stretching to iron out the twists. The material is moved into a stretcher with mechanical grips. It will be pulled into a full stretch and brought into specs.

10. Sawing and Cutting

The final step is sawing the extruded material into specific lengths. Once they are cut, they are moved into an aging oven for tempering to match the T5 or T6 tempers.

Once the extrusion process is completed, the material can be treated with other techniques and final fabrication to achieve the proper dimensions.