Aluminium is naturally corrosion resistant because, when exposed to air, it forms an oxide layer which protects the parent metal from corrosive elements. This protective layer can be artificially enhanced through the anodising process. This enhanced transparent layer can also be coloured or dyed during anodising to enhance its visual properties.
But what are the processes involved in anodising aluminium? And what are the benefits of anodised aluminium that make it so attractive?
How is Aluminium Anodised?
The anodising process was invented in the early 1920s and has been a popular method for enhancing aluminium ever since. The science involved in anodising aluminium is complex, but you don’t need a degree in chemistry to understand the basics of it.
The process involves submerging the aluminium into a series of baths or tanks. These tanks initially clean and rinse the surface in preparation for what is to come. The aluminium may then be submerged into an etching bath to give it a uniform matt appearance . It is then then that the aluminium is lowered into an acid electrolyte bath. An electrical current is then passed through the solution. The resulting reaction causes an oxide layer to form on the surface of the aluminium. This is not an additional layer, it is one that is created purely from the existing aluminium and is fully integrated into the metal. The thickness and quality of the aluminium oxide layer – also known as the anodic layer – depends on the current being passed through as well as the concentration and temperature of the solution. As you would imagine, the thicker the anodic layer, the more resistant to corrosion it is. Once the enhanced anodic layer has been formed it may then be coloured or simply rinsed and sealed.
The Benefits of Anodised Aluminium
A fantastic material, anodised aluminium comes packed with the following benefits:
- Corrosion Resistant: Anodising takes a naturally corrosion resistant material and enhances this property even further, allowing aluminium to be used in aggressive environments without losing its visual appeal and structural properties.
- Visual Aesthetics: Treating aluminium can often be at the expense of its natural sheen e.g. through powder coating. But the anodising process allows aluminium to maintain its lustre and maximise its visual qualities.
- Hard Surface : The anodic layer is as hard as glass and provides a practical surface that is resistant to wear and abrasion.
- Hygienic : Anodising creates a dirt repellent surface that can meet high standards of hygiene.
- Insulation : Gives surfaces an electrically insulated coating.
- Adhesion : Provides a good base for the application of adhesives or printing inks.
- Recyclable: Anodising is a treatment which is considered green and environmentally friendly. And this is down to the unique chemistry involved in anodising. As the aluminium oxide layer is created from the existing aluminium it remains 100% aluminium. With aluminium being one of the most recyclable materials available, anodised aluminium can be reused multiple times.
- Long Lasting: When it comes to the lifespan of the anodic layer there is virtually no finish line in sight. This makes anodised aluminium perfect for short term projects or for projects that are required to last for decades.
Anodised aluminium uses the power of science to underline its quality. Not only can it come to the aid of virtually any project you can imagine, but it will also provide numerous benefits. Therefore, when it comes to considering treatment options, anodising aluminium should be at the very top of your list.
For more information on whether anodised aluminium will be a good fit for your project, don’t hesitate to get in touch and speak to one of our team by phoning 01275 879995 or e-mailing firstname.lastname@example.org