Anodising and electroplating are two widely used surface treatment processes designed to improve the durability, resistance, functionality and appearance of metal components. Although they may seem similar at first glance, they differ significantly in both method and application. Understanding how they work helps determine which process is best suited to a particular use or industry.

How Anodising Works

Anodising is most commonly used on aluminium and works by thickening the metal’s natural oxide layer. In this electrochemical process, the metal part is placed in an acid electrolyte bath and connected as the anode. When electricity is applied, oxygen ions from the solution combine with the metal surface, creating a hard, corrosion-resistant oxide layer.

Because the coating is formed from the base metal itself, it doesn’t flake or peel. It also allows for colour treatments and sealing, making anodising suitable for both decorative and protective purposes.

How Electroplating Works

Electroplating involves depositing a layer of a different metal onto the surface of a part using an electric current. The component is submerged in a solution containing metal ions and connected as the cathode. As the current flows, metal is drawn from the solution and forms a thin coating on the item’s surface.

This technique is often used to enhance corrosion resistance, reduce wear or improve visual appeal. Common metals used include nickel, copper, gold and chrome. Here you can read in more depth about how electroplating works.

A variation of this process is electroless nickel plating, which does not rely on electricity. Instead, it uses a chemical reaction to apply an even layer of nickel across the component’s surface. This method offers excellent corrosion and wear resistance and is particularly useful for coating complex or internal shapes. It is used in industries ranging from oil and gas to precision engineering. Providers of this service include companies such as https://www.swmf.co.uk/surface-coatings/electroless-nickel-plating.

Key Differences

In summary, anodising modifies the existing metal surface, while electroplating and electroless nickel plating apply an additional metal layer. The right choice depends on the material, application and required performance.