The extrusion process itself makes the most of the metal’s unique physical characteristics. Aluminium’s impressive malleability means it is easy to machine and cast. But because the metal also has a third of the density and stiffness of steel it is both strong and stable, especially so when alloyed with other metals.

How does aluminium extrusion work?

First, the shape of the die is designed and the die itself created. Then a cylindrical piece of aluminium alloy is heated up. When it reaches the right temperature it is transferred to a loader where a lubricant is added to stop it sticking to the extrusion machine.

A great deal of pressure is applied to a dummy block and the ram pushes the aluminium into the container and through the die. Either liquid or gas nitrogen flows through the die, generating an inert atmosphere and increasing the die’s life while protecting against oxides.

The extruded result has the same profile as the die opening. Fans cool the extrusion on a special cooling table then it is moved to a stretcher where it’s straightened, work-hardened and cut to the right length. Finally the finished profiles are heated in age ovens, hardening the metal by speeding up the aging process.

It is possible to customise extruded parts by putting all sorts of interesting and intricate hollow sections, pins and piercing mandrels inside the die. You can also change the colour, texture and brightness of the metal’s finish, for example by anodising it.

What is aluminium extrusion used for?

Aluminium profiles are used for all sorts of purposes, from everyday applications to specialist settings like the International Space Station. The metal’s combination of strength and ductility, conductivity, non-magnetic properties and recycle-ability mean it can be re-used again and again without losing its integrity.

Because of all this, aluminium is extruded more often than any other metal and can be extruded hot or cold. Heat extrusion involves heating the metal to 300 – 600 °C. Either way, the end products are commonly used for making tracks, frames, rails, mullions and heat sinks, cars, trains, bikes, aeroplanes and boats, internal frameworks, hinges and clasps. Aluminium profiles even hold together the computer you’re reading this article on, and the keyboard you type on.

If you want to know more about aluminium profiles, extrusion products and even aluminium plate, suppliers like us have the knowledge you need. Just ask.

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