In recent years, aluminum extrusion have become highly popular in product manufacturing, especially in the automotive industry. Lightweight yet durable, aluminum extrusions offer a whole host of benefits.
Because of this, the worldwide sales of aluminum extrusions are expected to result in a market value of $89 billion this year. This is expected to reach $175 billion throughout the following decade.
However, you may be wondering how aluminum extrusion profiles are created. What’s the extrusion process entailed? Below, we are going to take you through the aluminum extrusion process in full so that you can get a better understanding.
Preparing the extrusion die
We start the aluminum extrusion process by machining a round-shaped die unless we have one readily available.
We preheat the die to approximately 450-500 0C. This will make sure there is an even metal flow and optimize the die’s lifespan. Once we have finished preheating, the die can be loaded onto the extrusion press.
Preheating the aluminum billet
An aluminum billet is a thick cylindrical aluminum alloy block. We will need to cut this. We preheat the billet in an oven set to approximately 450-500 0C. This is an important part of the aluminum extrusion process, as it ensures the billet is not molten and is malleable enough to carry out the operation.
Transferring the billet to the extrusion press
We add a lubricant and then load the billet onto the press mechanically. We also apply the release agent to the extrusion ram. This part of the aluminum extrusion process stops the billet and ram from sticking together.
- Pushing the billet into the press container
The malleable billet should be in the extrusion press now. So, we are ready to apply pressure using the hydraulic ram. This pressure will push the malleable billet into a container. The aluminum materials will then expand, filling the container’s walls.
- Pressing the extruded material onto the die
The aluminum material is now pressing against the extrusion die. Pressure is continually being applied to the material. Therefore, the die openings are the only directions possible. The material will emerge from the die’s openings in a fully-formed shape.
Now, we move on to the quenching part of the extrusion process. This involves the alloy being moved along a table while a water bath or fan cools the profile. A puller holder will make sure the extrusion is kept in place.
- Shearing the extrusions to table length
We use a hot saw to shear the extruded aluminum once it reaches the length of a full table. It is important to note that temperature is key at every part of the aluminum extrusion process. Although we have just quenched the extrusion, it is not fully cool at this moment.
- Cooling extrusions to room temperature
Once we have finished shearing, the extrusions should be transferred to a cooling plain from the runout table. The profiles will remain here until they reach room temperature. Stretching will then take place once they reach the desired temperature.
Moving extrusions to the stretcher and then stretching them into alignment
At this stage, there are some twists in the shapes. So, we will now correct them. To make the correction, we use a stretcher. We will hold each profile mechanically on both ends, pulling them until they are completely straight. This process is critical to bring the aluminum extrusion profiles into specification.
- Cutting extrusions to length
Now that we have made the extrusions work-hardened and straight, we will transfer them to a saw table.
At this point, we cut them into specified lengths. Once this is done, the pieces will be transferred to an oven and aged to the right temperature.
- Completing any secondary operations
Once the extrusion process is finished, profiles can be treated with heat so that the properties are boosted.
Fabrication will typically happen next if dimensions need to be corrected.
Also, a surface finish is sometimes added to boost corrosion resistance properties and enhance the appearance of the aluminum pieces.
The aluminum extrusion process explained
As you can see, there is a comprehensive and precise process entailed when it comes to aluminum extrusion. This is often adapted based on the specific order, but we hope that this helps you to get a better understanding of what is involved.