The Aluminium Extrusion Process
An Overview

What is aluminium extrusion?

In essence, the extrusion process involves heating a piece of aluminium known as a Billet to temperatures in excess of 500 degrees Celsius. Whilst the metal is still hot, the Billet is forced through a steel die, entering as a solid piece of aluminium or alloy and exiting as a cross-sectional shape or ‘profile’.

The combination of heat, lubricants and the enormous amounts of pressure that are exerted upon the aluminium when being forced through the die ensure it can flow through the die smoothly. This results in a quality product, manufactured and measurable to very high tolerances.

Aluminium – Versatility and reliability

The extrusion process exploits the very best of aluminium’s properties as a versatile material, in fact the versatility of the two – process and metal – complement one another excellently. Aluminium and its related alloys have a very high strength-to-weight ratio in relation to its ductility or malleability. With the right application of heat and pressure it can be manipulated into almost any shape or cross-sectional profile.

The complexity of a proposed profile for extrusion, irregardless of the need for very high tolerances is generally rendered irrelevant by its versatility as a product, meaning aluminium is an ideal material for design applications requiring maximum versatility. There are also over 540 aluminium-alloys available for extrusion, each of which have their own properties and relevant applications. As a general rule, the richer in aluminium a Billet is, the more easily extruded or the more malleable it is.

So why choose extrusion?

Extrusion gives designers and manufacturers select opportunities that cannot be achieved through other machining or manufacturing processes. For example, extrusion enables the production of cross-sectional profiles with a variety of special functions such as joining details, channels and grooves or structural ‘stiffeners’.

This results in less waste and reduced fabrication costs when compared to other products such as rolled steel fabrications. In addition, the relatively low costs of extrusion allow companies requiring a smaller production series can work more freely within their budget.