Treatments / Hard Anodization

Hard Anodization

Hard anodized surfaces by CERANOD^® are mainly used for fast moving parts. As an enhancement of natural anodization, ELB produces considerably thicker, harder and more wear-resistant oxide hydrate layers. By incorporating PTFE (polytetrafluoroethylene), the coefficient of friction can be reduced significantly.

By the process of hard anodization, about one half of the layer thickness grows outward the surface, since the hard oxide has a larger volume than the aluminum substrate. This change in dimension must be considered during the mechanical production.

The layer is built out of the substrate material. Thus, the highest possible adhesion between the layer and the base metal is achieved. The color of this oxide layer depends on the alloy and on layer thickness. It varies from light bronze to anthracite.

The pore structure of the hard anodized oxide layer is suitable for incorporation of color pigments. These can be stored and enclosed in the pores of the oxide hydrate tubes so that the color remains firmly anchored.

To find the best solution, we redefine parameters and electrolytes and adapt them to the specific requirements of our customers. A reliable knowledge of the material is essential for the results of our processes. With the help of X-ray fluorescence analysis, we identify the optimal treatment in advance and anodize the material according to the alloy. This enables us to react to fluctuations even during the process.

Special alloys of the Al EW 2,000 and the 7,000 series, as well as alloys that cannot be anodized according to DIN, can be treated with our surface technology.

Areas of application for hard anodized surfaces are:

• shipbuilding
• chemical industries
• computer engineering
• electrical engineering
• gas turbine parts
• hydraulic equipment
• pistons
• medical devices
• pumps
• special mechanical engineering
• shock absorbers
• ventilators
• gear wheels
• cylinders
• aerospace