What Anodising Does for Aluminium Parts
Anodising is a process that transforms the outer layers of aluminium into a strong and stable aluminium oxide. It is a surface finish that can be produced in various forms and properties, to meet the requirements of various applications.
Corrosion Resistance
The surface of anodised aluminium forms a chemically stable aluminium oxide layer. It has a strong bond with the underlying aluminium and is not a coating that can peel off like paint. Therefore anodised parts can be used in outdoor applications and in humid environments without developing white corrosion similar to that which untreated aluminium surfaces can get.
Increased Surface Hardness
The anodised surface is significantly harder than the substrate aluminium. Standard sulphuric acid anodising produces a surface hardness suitable for light wear, while hard anodising produces a thicker, more dense layer, which is ideal for sliding applications, tooling and other high wear components that are subject to constant mechanical stress.
Electrical Insulation
Anodising converts a good conductor of electricity into a good electrical insulator, a property which is often exploited in electronics to make housings, heat sinks, etc. from aluminium. Also, in many engineering applications aluminium parts are assembled together using adhesives, and the anodic film provides a surface for good priming for paints, and for adhesives.
Better Adhesion for Primers and Adhesives
A freshly anodised surface has a porous structure, which provides an ideal ‘key’ for primers, paints and most structural adhesives. This is why anodising is specified before bonding in many applications, particularly in the aerospace and automotive industries. If you want Anodising, https://www.poeton.co.uk/surface-treatments/anodising is a good place to start.
Understanding the properties of anodising will enable you to decide if anodising is required or not for your specific item.
