Aluminium is often referred to as a ‘corrosion resistant’ metal. What does this mean? Whymight a designer specify ‘anodised’ aluminium?

When we say that aluminium is a 'corrosion resistant' metal, it means that aluminium has a natural, protective layer of aluminium oxide on its surface that protects it from damage. This layer is highly resistant to corrosion, which is the gradual destruction of materials by chemical reactions with their environment.

The term 'anodised' refers to a process that increases the thickness of this natural oxide layer. During anodising, an aluminium object is placed in a special electrolyte solution and an electric current is passed through it. This causes the oxide layer to grow.

A designer might specify 'anodised' aluminium for several reasons. Firstly, anodising makes the aluminium more resistant to corrosion, which can be beneficial in harsh weather conditions or in contact with certain chemicals. Secondly, anodised aluminium has a very attractive, metallic look, and it can be dyed in a variety of colours. This makes it a popular choice for many design applications. Finally, the anodised layer is also a good base for painting or adhesive bonding, providing more options for finishing the product.