Anodised Aluminium - Process, Benefits and Popular Colours

9 minutes 30 seconds read

17 Aug 2023

Anodised Aluminium - Process, Benefits and Popular Colours

Anodised Aluminium - Process, Benefits and Popular Colours

Aluminium is a versatile, lightweight and hard-wearing metal that’s used for a variety of important applications – from construction and engineering to automotive production. While it has naturally strong rust- and corrosion-resistant properties, it can be affected by pre-rust and certain forms of corrosion. It’s also known for its natural shine, but this too can be prone to scratches, depending on how it's used.

Fortunately, there is a solution. Anodised aluminium boosts the corrosion-resistance and durability of raw aluminium – along with a whole host of other benefits. In this article, we’ll cover everything you need to know about anodised aluminium, including its key benefits and applications.

Article in Brief

Anodised aluminium refers to aluminium that has gone through a process of controlled oxidation.

The benefits of anodised aluminium include its corrosion and scratch resistant properties, stylish and customisable aesthetics, long lifespan, and eco-friendly production.

Popular anodised aluminium products include anodised aluminium angle, sheet and tube.

Anodised aluminium can be dyed a variety of colours, including black, silver and gold. It’s also possible to paint anodised aluminium.

Both raw and anodised aluminium have many benefits, so it’s important to consider which is right for your project. It’s worth spending extra for anodised aluminium if you need extra scratch and rust resistance. However, if you only need aluminium for its strong yet lightweight properties, then raw aluminium is the most cost-effective choice.


What is Anodised Aluminium?

If aluminium has been anodised, it has gone through a process of controlled oxidation. This improves the thickness of the natural oxide layer on the surface of the aluminium.


How is Aluminium Anodised?


In the pre-treatment phase, the aluminium is cleaned to remove any dirt or oils, then etched to remove minor imperfections.

Anodising Aluminium

After this, the aluminium is anodised, either in chromic acid or sulfuric acid. This works by submerging the aluminium in an acidic electrolyte bath, which has an electrical current running through it.

First, a cathode is mounted within the anodising tank. The aluminium acts as the anode. An electric current is then passed between the anode and cathode. Oxygen ions are released from the electrolyte. These ions combine with aluminium atoms, forming aluminium oxide. This creates an anodic oxide barrier layer across the surface of the aluminium.


As the oxide layer is fully integrated with the aluminium substrate, this creates a surface that is both resistant to flaking and peeling, whilst also being porous enough to facilitate the applications of dyes, paints and adhesives.


Benefits of Anodised Aluminium

Corrosion and scratch resistant

The aluminium oxide layer reinforced through anodising is highly corrosion-resistant, making it suitable for use in even the most extreme conditions. Anodised aluminium is also more resistant to scratches than the raw material, and it’s very easy to clean with just soap and water. So, you won’t have to worry about unseemly scratches, chipping or flaking.


Whatever style you choose, anodised aluminium will always look great. As the oxide layer is integrated with the aluminium substrate, the natural, stylish appearance of the metal will be kept intact. Or, if you’d like a particular colour, there are plenty of options for dyeing or painting the aluminium. For example, black anodised aluminium is a very popular choice.


Anodised aluminium is highly durable, with a drastically extended lifespan compared to the raw material. Even within volatile environments, such as marine locations, the highly resistant properties of anodised aluminium ensure it stays in great condition.

Environmentally friendly

Another great detail about anodised aluminium is that it has a low environmental impact. For one thing, the production process does not produce solvent emissions or CO2. What’s more, anodised aluminium is fully recyclable. The remelting process uses only a tiny amount of the energy required to produce new aluminium.


Popular Anodised Aluminium Supplies

The anodising process can be applied to a range of different aluminium profiles for use in your projects. Some of the most popular options include…

Anodised aluminium extrusions

These include a wide variety of supplies, such as aluminium angle, tube, flat bar and channel.

Anodised aluminium angle is a popular choice. This is used to hide and protect corners and edges, as well as covering fixtures and creating decorative borders. The corrosion- and scratch-resistant properties ensure that anodised aluminium angle will look fantastic for years to come.

Another popular extrusion is anodised aluminium tube, which is typically used for mechanical, fabrication or construction purposes. They can be dyed a variety of different colours, making them suitable for use in furnishings.

Anodised aluminium sheet

From vehicle construction to aviation, anodised aluminium sheets have a variety of applications. Their durability, corrosion-resistance and stylish appearance make them a clear choice for construction projects.


Will Anodised Aluminium Rust, Peel or Scratch?

No, you won’t have to worry about rusting with anodised aluminium. Whilst aluminium is naturally resistant to rust, anodising aluminium optimises the material’s rust-resistance, along with its corrosion- and scratch-resistant properties. Anodising also provides a more uniform appearance, ensuring the highest-quality finish for structural and furnishing applications.


Standard Colours for Anodised Aluminium

It’s possible to dye anodised aluminium due to its porous structure. Though it varies between suppliers, popular colours include:

  • Black
  • Silver
  • Gold
  • Copper
  • Blue
  • Orange
  • Yellow
  • Red
  • Green
  • Purple
  • ...and more

Alternatively, it’s entirely possible to paint over anodised aluminium, so you can choose the colour that suits your requirements. It’s recommended to clean the aluminium after the anodising phase to remove any contaminants, such as grease, as these can make painting the surface more difficult. Once this is complete, primer should be applied immediately to reduce the risk of other contaminants affecting the aluminium. After carefully sanding the surface to remove imperfections, the paint can be applied.


Is Anodised Aluminium Worth It?

So, is anodised aluminium worth it? Ultimately, it depends on what you’re using it for.

Raw aluminium has great benefits on its own – including rust-resistance, a good-strength-to-weight ratio, and a long lifespan. However, anodised aluminium boosts all the properties that makes aluminium such a fantastic material. Aside from preventing corrosion, scratches and peeling to the surface of anodised aluminium angle, sheet and tube, it can also create colourful decorative effects.

Anodised aluminium ensures your aluminium stands the test of time – and looks great too. However, that does come with a higher price tag. So, it’s important to consider whether the benefits outweigh the costs. If your project requires aluminium that will stay looking great, with no scratches or corrosion, then anodised aluminium is likely to be the best solution. It’s also a good option if you need to dye or paint aluminium, or if an eco-friendly material is a must.

If none of these factors apply to you, then anodising aluminium may be an unnecessary expense that will only add your costs. In this case, it’s usually better to go with the raw material.

Anodised Aluminium Suppliers in the UK

Searching for aluminium that will look great for years to come? As one of the UK’s leading anodised aluminium suppliers, The Metal Store is here to help!

Whether you’re looking for anodised aluminium angle, round bar or sheet, you’ll find exactly what you need in our collection. We offer anodised aluminium supplies throughout the UK – with a free cutting service to trim your order to size.

To learn more, get in touch on 01274 875 479 or send an email to [email protected].

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