Chromic Acid Anodisation
Chromic acid anodisation
Chromic acid anodisation is an alternative to sulphuric acid anodisation, which is used where a layer is required with high corrosion resistance and good adherence ability.
Advantages:
- Especially suitable for aluminium blanks with a lot of cavities, rivets, etc. as residues of chromic acid do not attack the metal in the same way as sulphuric acid
- Very suitable as a pre-treatment for gluing and lacquering due to its good adherence and corrosion protection
Application:
- Aviation
- Armed forces
Structure and appearance after treatment:
- The impression of metal is retained
- The anodisation layer is transparent
- The colour becomes light grey
Layer thickness:
- 2-5 µm
- The covering appears in different grey tones according to the alloy
Colouring:
- Can be coloured in different dark colours
- The covering is sealed in warm water if it is not to be further surface treated
Alloys:
- The majority of alloys can be used
- Cast alloys should not be used
- Alloys with over 5 % copper should not be used
- As a pre-treatment for lacquer and gluing the covering must not be sealed