Anodizing

Anodizing

Anodizing is an electrolytic process used to provide Aluminum parts with a thick oxide layer. This generated oxide layer is hard, porous and wear resistant. An additional sealing of the, through the process formed pores further improve the corrosion resistance.

To perform the anodizing process various types of electrolytes can be used. Depending on the base material as well as the requested properties of the anodizing layer, the electrolyte and process type are chosen.

The anodizing process consists the following steps

  • Cleaning. By removing oils and decontaminations covering the naturally shaped oxide layer the base material is cleaned.
  • Eventually reducing of the material thickness by etching with a pickling agent to reach the original dimension (the so-called dimensional stable anodizing).
  • Anodizing. The coating is performed in an electrolyte (sulphuric or chromic acid) at temperatures slightly below room temperature. The parts are connected with the anode and, in the course of the treatment, the parts surface is converted into an Aluminum oxide layer. After build-up, the Aluminum oxide layer can be colorized with various color pigments.
  • Sealing of the Aluminum oxide crystals by hot water.