Abstract
The synthesis of oxides in a low-temperature electrolytic plasma allows to cover surfaces of magnesium and its alloys with multifunctional protective oxide-ceramic coatings. In order to optimise the technological process and layer properties various process parameters have been changed (current density, ratio of anodic to cathodic current and electrolyte composition) and the influences on layer structure, composition and properties with a main focus on corrosion behaviour were studied.
The corrosion properties of the various layers were studied in 5% NaCl solution by (a) analysing the corrosion morphology, (b) measuring electrochemical polarization curves (pH 10) and (c) immersion tests at constant pH-value (pH 6). Additional information was obtained by locally resolved EC-Pen measurements. By using XRD, LM, SEM and EDX to evaluate the composition and microstructure of the modified surface before and after the corrosion measurements, the corrosion results will be related to the microstructure and composition of the specific layer. Furthermore the influence of the process conditions on the microstructure and composition will be discussed.
DOI Link to Publication