What is Aluminium Extrusion?

Aluminium extrusions are made from aluminium that has been pushed through a die of a specific shape or profile, resulting in a continuous cross-sectional piece. This is known as the aluminium extrusion process. The process allows for various shapes and sizes to be created, ranging from simple flat bars to complex multi-void profiles.  

Aluminium extrusion is popular thanks to aluminium’s favourable properties and multiple benefits, such as its light weight, strength, corrosion resistance and conductivity, combined with the aluminium extrusion process’s ability to create various complex and integrated shapes. These benefits make aluminium extrusions ideal for use in numerous industries for various applications, including aerospace, automotive, electronics, construction and more.  

At LA Metals, we supply various aluminium extrusion products in assorted dimensions and can even cut to size for your unique requirements. Check out the UK’s greatest aluminium extrusion range.  

The Basics of Aluminium Extrusions

The basics of aluminium extrusions involve understanding the materials, the benefits, the applications as well as the aluminium extrusion process. Here is a breakdown of the factors involved.  

  • Material – Aluminium Alloy 
    Aluminium alloys are chosen based on the required properties such as strength, ductility, corrosion resistance and workability. The alloy composition can include elements like silicon, magnesium and zinc to improve the properties and typically will be based on alloys 6061, 6063 and 7075. 
  • Basic Benefits 
    The benefits of working with aluminium extrusions are many and include design flexibility to create complex shapes and additional customisation and its lightweight yet strong properties making it ideal for applications where support is required, and heavy materials would be a hindrance. It also has great thermal conductivity, is cost-effective and sustainable and offers a stylish finish. 
  • Applications 
    Aluminium extrusions are everywhere you look, from architecture to transportation, electronics to consumer products, industry, machinery, infrastructure, construction, energy and more. You can find it in solar panels and window frames, exercise equipment, structural components, marine fittings, conveyor systems, wind turbines and supporting bridges and rails. 

What is the Aluminium Extrusion Process?

The aluminium extrusion process involves transforming aluminium alloy into objects with a definitive cross-sectional profile for a wide range of uses. The process is achieved by forcing heated aluminium alloy through a die, which has the shape of the desired cross-section.  

The Five Steps of Aluminium Extrusion

The process can be outlined in six primary steps, from the initial design phase to the final finishing treatments. Please, see the order and steps below.  

  1. Design and Creation of the Die 
    The first step is designing and creating the die, which is a steel tool used to shape the aluminium.  
  1. Billets Preparation 
    Aluminium alloy is cast into long, cylindrical shapes known as billets. These billets are cut and heated to make them malleable but not molten.  
  1. Extrusion Process 
    The heated billet is then pushed through the die by a hydraulic ram. As it passes through, it takes on the cross-sectional shape of the die.  
  1. Cooling 
    The profiles are then cooled using water or air to help solidify the aluminium into its new shape.  
  1. Stretching 
    The extruded aluminium is then stretched while still soft to straighten it and relieve internal pressures from the cooling process.  
  1. Cutting and Finishing 
    The long aluminium extrusions are then cut to length and can be finished with anodising, painting, powder coating or polishing if desired. 

Factors Affecting Aluminium Extrusion Success

Aluminium fabrication is very important for many applications in modern life, so it is handy to know about all the factors that can affect the aluminium extrusion process. These include the die design and quality, the aluminium alloy selection, billet preparation, extrusion parameters, cooling and quenching, stretching and straightening, heat treatment, surface finishing and handling and storage.  

By carefully considering and optimising these factors, manufacturers can improve the efficiency of the extrusion process, enhance the quality of the extruded products and meet the specific requirements of their applications.  

Visit LA Metals, the UK’s number one supplier of aluminium extrusions and discover our wide range of shapes, lengths and finishes.