Chromic Anodising

We offer Chromic Anodising using Chromium Trioxide in accordance with Def Stan 03-24.

Overview: The chromic anodising process is used where a high resistance to corrosion is required, where crack detection is a subsidiary requirement, for the treatment of aluminium assemblies where there must be no corrosion risk from trapped electrolyte (a common problem with sulphuric anodising) and for the production of opaque enamel-like self coloured grey/black finishes for decorative use.

Key Strengths: There are a number of key features that make chromic anodising key for particular applications:

• Ideal for castings
• Minimised loss of fatigue strength due to anodising
• No risk of sulphuric acid entrapment and associated post treatment corrosion
• Ideal for treatment of material less than 0.25mm thick
• Compatible with explosives, propellants and pyrotechnics

Applications: Typical applications include aerospace, defence and foritems used in marine environments where exposure to salt is high.

Tanks: We offer tank sizes up to 5' x 5' x 3'.

Thickness: Standard coating thickness is 2µm.

Finish: All chromic anodised finishes are grey but can be dyed blue or black.

Copper: Chromic anodising is unsuitable for alloys containing more than 5% copper.

Jigging: Correct jigging is essential to the resulting finish, and good jig points are required, a consideration that should be made at the design stage of a component. The use of loose, sliding or intermittent contacts will result in an unsatisfactory connection and give rise to faults such as thin coatings, burning at the contact points or even failure to obtain an anodised coating.