Plasma electrolytic oxidation (PEO) is the only way to anodize magnesium as to improve corrosion resistance of magnesium and its alloys by forming a ceramic oxide layer. PEO treatment involves the formation of spark.
A new electrolyte to anodize magnesium has been developed by CIDETEC, being its main advantage the possibility to get high thickness, up to 50 microns, in short times with low energy consumption and keeping the typical high hardness of the PEO layers (> 800 HV).
Lightweight components with high strength are increasing the industrial interest in sectors such as aeronautics, aerospace and automotive to the replacement of the conventional metals (iron and steel) by light metals, especially magnesium.
Microscopic image of a magnesium anodizing layer (on top & cross section).
The use of magnesium (offering a low standard electrode potential -2.37 V) and its alloys in different applications is limited due to its low corrosion resistance, particularly to galvanic corrosion. Thus, surface treatments are fundamental to improve corrosion performance of these materials. On one side layer thickness is critical for this purpose but some electrolytes shown thickness limitations. On the other side PEO treatments have a low wear resistance.
Improved corrosion resistance
Visual image after corrosion test for unsealed and sealed specimens (Neutral salt spray and galvanic corrosion)
Improved wear resistance
Visual image after tribological test for unsealed and sealed specimens
Aeronautics
lighter structures and engine housings which reduce fuel consumption.
Automotive
lighter and resistance car structure such as roofs or frame windows.
Telecommunication
lighter antennas with magnesium components make easy their installation.
Electronic devices
lighter devices with magnesium housings that make easy their use.