Treatments / Natural Anodization

Natural Anodization

Anodization is the classical surface refinement for aluminum.

Anodic current in an acidic electrolyte produces an extremely resistant aluminum oxide hydrate on the surface of the soft aluminum.
In contrast to painting or electroplating, no additional layer is applied to the base material. The anodized layer is made up of the material itself and, thus, is covalently bonded to the light metal – even on inner surfaces and undercuts of smallest parts.

The CERANOD^® anodic layer grows columnar – depending on the alloy and process – two-thirds into the metal and one-third outwards. This change in dimension is particularly important when working with high precision parts.

Recommendations for the anodizability of different aluminum alloys can be found in the corresponding DIN EN 573-3 and DIN EN 1706 standards.

Surface defects are not corrected by this surface treatment. Moreover, damages of the surface, topographical differences, other characteristics, or impurities are still visible after the anodizing process. Therefore, the greatest attention must be paid to the pre-treatment of the material. In addition to cleaning, chemical etching or satin finishing, various mechanical finishes such as blasting or, grinding, brushing can also be used. All these pretreatments are covered in-house.

Since the Aluminum oxide layers are microporous, this pore structure is very suitable for storing color pigments in the oxide hydrate tubes. After this, the pores can be enclosed by a subsequent sealing process to protect the color pigments.

To achieve optimum results at any time and to be able to respond to the slightest process fluctuations, we take a close look at the difference of alloys and tailor our processes precisely to them. We handle each customer project individually, working out the suitable program in our fully automated production. This guarantees top quality and exact reproducibility of the desired anodization.