You might not consider anodising during your day-to-day life, but actually, the results of the anodising process can be seen in action everywhere. From the smooth finish of a bike frame to a piece of cookware you use everyday, chances are you’ve passed by an anodised item today. But what exactly is it, and why is it such a popular treatment for metals such as aluminium? Here’s our handy guide:
What is anodising?
Anodising is an electrochemical process which converts the surface of a metal, usually aluminium, into a durable and corrosion-resistant oxide layer. It’s a different process to paint or plating, which involves applying a layer on top of the metal’s surface. With anodising, the anodised layer actually becomes part of the metal itself. There are real benefits here, because this means it won’t chip or peel off, and anodising adds both protection and a clean, visual finish.
The word ‘anodising’ itself comes from the fact that aluminium acts as an anode – a positive electrode – in an electrical circuit. The metal is placed into an acid electrolyte bath and an electrical current is passed through it. When the current flows, oxygen is released at the surface of the aluminium. This creates a layer of aluminium oxide. This process can be completed by expert companies, such as www.poeton.co.uk/surface-treatments/anodising/.
Why anodising?
Anodising is really useful because it creates corrosion resistance – the oxide layer will protect the metal from the environment and moisture, making it great for applications outdoors, for example. It also looks great once complete, as the aesthetic finish and porous nature of the surface means it can be dyed in a range of different colours for visual appeal. It’s also very durable, as anodised aluminium is harder than its untreated counterpart, meaning it’s more resistant to scratches and wear and tear. What’s more, it’s more environmentally friendly than some other coating or painting methods and is quite a clean process overall.
What metals?
Aluminium is by far the most commonly anodised metal, but there are other non-ferrous metals that can be anodised.