Anodising Aluminium

Aluminium alloy anodising services sometimes known as oxide powder coating for a wide variety of components and parts can:

• Increase resistance to wear and corrosion.
• Allow and increase the ability of parts to retain coloured dyes.
• Improve the lubrication and adhesion properties of the alloys.
• Reduce (thermal) conductivity and the (coefficient of linear) expansion.
• Increase electrical insulation.
• Reduce galling in parts where there is contact e.g. components that are threaded.
• Produce a hard surface and reduce cracking and the effects of wear and tear over time.

Anodising of alumnium alloys essentially involves causing the metal to build up a natural and uniform oxide layer on the surface which is thicker and more resistant to negative wear and corrosive effects than that caused by these alloys being naturally exposed to gasses containing oxygen (also known as self passivation). The creation of this anodic film or powder coat is achieved by making the alloy act as the 'anode' in electrolysis using sulphuric acid as the conducting solution in the process. The porous nature of this thick oxide layer is what allows dyes to be taken so well, and a sealing process after the initial anodising helps to prevent any air or water reaching the metal substrate or causing corrosion.