Plasma Electrolytic Oxidation - SFB CRC 1316 Project B5
Plasma electrolytic oxidation belongs to the huge and growing research field of plasmas in liquids. It is a plasma-enhanced anodization process for light-weight metals like aluminum, titanium and magnesium, as well as their alloys. Contrary to classical anodization processes, which are usually processed with voltages up to 25 V DC, voltages of a few hundred Volts are used for plasma electrolytic oxidation. After reaching a so-called breakdown voltage, microdischarges appear stochastically distributed on the substrate surface and extinguish after a few to a few hundreds of microseconds. These microdischarges melt the electrolytic coating and lead to harder coatings with enhanced adhesion to the substrate material. The resulting ceramic coatings provide exceptional corrosion properties, are strong bound to the substrate and enable in the first place the use of the substrate materials for varying applications. For instance, this technology enables the use of magnesium alloys as material for dental implants or bicycle frames. Nevertheless, these microdischarges leave holes and defects on the coatings, the so-called pancake structure, which affects adversely the coating properties. Therefore, an understanding of the fundamental plasma processes is essential for the application-specific design of plasma electrolytic oxidation processes.
In the frame of project B5 '2D-plasma-liquid-solid interfaces – plasma electrolytic oxidation' of the Sonderforschungsbereich SFB CRC 1316 we work on the investigation of fundamental plasma parameter and knowledge-based control- and optimization concepts for plasma electrolytic applications.