Anodizing is a surface treatment process applied to aluminum or titanium alloy parts. This surface treatment firstly makes it possible to protect the parts, giving them better resistance to wear, heat or the ability to withstand corrosion (anti-corrosion). Secondly, it allows the parts to be decorated; in addition to colorless anodizing, color anodizing (tinting) offers a wide range of colors while preserving the natural metallic appearance of the material.
The steps of anodizing:
– The aluminum part is placed in an electrolytic bath of dilute sulfuric acid and connected to the positive pole (anode). The reaction that occurs removes the natural oxide layer of aluminum and deposits a new thicker layer of aluminum oxide (or alumina). During this process, the new layer formed can absorb pigments or other substances.
– There are two options depending on the desired appearance: transparent layer or customized coloring. When this layer of aluminum oxide has been formed, it can accept pigments to color the part. Metallic colors can thus be applied perfectly and any color is possible.
– Filling/sealing step during which the pores are compacted and stabilized in the layer, thus transforming the surface into a closed layer. This results in a corrosion-resistant anodized layer that remains clean and maintains its color.
Once treated, the surface of the anodized aluminum not only has excellent corrosion resistance, but also preserves its color and remains clean. It will always be possible to then apply a surface finish such as by micro beads blasting.