Aluminium Extrusion is the procedure used to add lengths to aluminium or make a cross-section. When talking about extrusion it seems daunting, and even though the process is hard, the outcomes are worth it. You’ll be left with a great surface finish and exceptional strength. There are only a few aluminium shapes that can be extruded…
- Beams, Rods, or Angles because these have no opening and are most likely solids.
- Square or Rectangular objects that have one or more openings, such as an aluminium box section.
In many industries like Construction, Aircraft Manufacturing, Automobile, and Industry machinery, an aluminium suppliers capable of aluminium Extrusion is popular because they’re lightweight and have durable strength, which is a popular choice for the Aerospace industry.
The two most common ways of conducting the extrusion process are Direct Extrusion and Indirect Extrusion.
Direct extrusion is also known as forwarding Extrusion, and a lot of companies use this method. This process works by using the Billet in a heavy-walled container. Then the billet is pushed through the die head by a screw or a ram. Then there is a reusable block between the billet and ram and make sure to keep them separated. Direct extrusion is used in manufacturing companies that use hollow tubes, solid rods, and bars. The design of the die head can be modified to assemble a wide variety of hollow or solid profiles. Direct extrusion can be used to make products with cross-sections like bricks, pipes, and more.
In addition, Indirect Extrusion is known as backward extrusion and this process is not that known compared to direct. This process is when the die head is continuously moving by itself, but the billet and container are moving together. This works because when keeping the billet stationery, keeps friction to a minimum. Before the extrusion process starts a cross shape is designed. The shapes and features of the metal are calculated beforehand to ensure that it facilitates the assembly line. Reduction of weight and minimizes finishing costs. What makes aluminium popular is that its good value for money and its nice design. Lastly, to keep the die stationary an object called stem is involved which must be longer than the container.
What exactly is the difference between Direct and Indirect extrusion?
With direct extrusion, the press pushes the billet which then goes through the fixed container and the die presses the ram. But what’s different is that Indirect extrusion used the billet while it is in a fixed position, then the die is pushed into a container holding the billet
The Aluminium Extrusion process…
- A die is made from a cross section of the desired/ shape they want.
- Then using a furnace heat the Aluminium billets to 750-925ºF. This will then make the aluminium become a soft solid.
- A substance called Smut is applied to the bat and ram. The smut makes sure the billet and ram don’t stick together.
- The ram then applies pressure to the billet, thrusting it through the die. While this process is happening, Liquid nitrogen is used to cool down the die because it gets too heated and helps prevent nasty oxides from forming and making the die longer.
- The aluminium, which is extruded, appears from the die, the die then proceeds to take on the same shape as the die opening. Then the extrusion is put onto a cooling table where it can be exposed to Water and Air. This will remain on the table until it goes to room temperature.
- Afterwards, a stretcher is then applied. Then each of the profiles are stretched until they’re straight. Some of the extrusions may be up to 50 meters long!
- When straightened they are put onto a saw table, were they’re now cut to their specific lengths usually between 8-21ft.
There are many benefits to Aluminium and Extruded Aluminium
- Aluminium is very affordable which is why many companies use it.
- When extruded Aluminium becomes very strong and durable. Also, when the temperature drops, the aluminium doesn’t shrink making it stronger.
- Aluminium doesn’t rust because the surface area is protected by oxide, and this can increase by Anodizing.
- Aluminium conducts heat better than most metals.