Anodising

70% of our manufactured components have a finished coating, so we do carry a enormous amount of knowledge in this area, so if you have any questions about a finish coating please contact us and we will do are best to answer your query, or take a look at the brief description below about the finishes that we carry out.

Anodising is an electrochemical process used to produce durable and decorative finishes on components made of aluminium or aluminium-based alloys.

Aluminium, in an untreated form produces a protective oxide coating on exposure to the atmosphere. This oxide is inherently protective, but being very thin provides little resistance to long term corrosion. The coating can, however, be thickened by anodising.

The 3 main types of anodising process in regular use are:

Sulphuric acid anodising
Hard anodising
Chromic acid anodising

Sulphuric acid anodising
Sulphuric acid anodising which is extensively used for general industrial and architectural applications, produces a coating (typically silver or pale grey) which can be left natural or dyed to produce a wide range of colours. The translucent nature of sulphuric acid anodic oxide coatings enables them to be used on aluminium in conjunction with a wide range of chemical and mechanical pre-treatment.

Hard anodising
Hard anodising covers a number of processes which are based on the use of specialist acid solutions and high voltage and current density electrical conditions, to produce particularly hard anodic oxide coating with excellent wear and corrosion-resistant properties. These coatings have particular advantages on aluminium used for specialist engineering components where the properties of lightweight plus a hard surface are of particular benefit.

Chromic acid anodising
Chromic acid anodising is normally used for the protection of aircraft and specialist engineering components that require only a thin anodic coating, or for crack detection in castings or forgings. The dove grey finish is often used as a pretreatment for painting, or to give corrosion protection while allowing electrical contact.

In contrast to traditional methods of electroplating the relatively new process of Electroless Nickel coating gives present day specifiers an exciting answer to many metal finishing problems. An electroless Nickel film is produced by chemical deposition of Nickel ions from a complex Nickel salt solution. The coating can be applied to a wide range of substrate material, varying pre-treatments are used to prepare for plating through cleaning and activation so as to give excellent adhesion properties. Post treatments such as heat treatment or subsequent coatings may be applied on top of the Nickel coating.

Further infomation

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