Microscale morphology and properties of the PEO-coating surface

The features of the corrosion process in the artificial defect on the coating obtained by plasma electrolytic oxidation (PEO) method on magnesium MA8 alloy have been investigated using the Localized Electrochemical Impedance Spectroscopy (LEIS), Scanning Vibrating Probe (SVP) techniques along with the Non-Contact Optical Surface Profiler (OSP) technique. The analysis of the experimental data enabled us to suggest that the corrosion process in the defect zone developed predominantly at the magnesium/coating interface. The LEIS technique allows detecting the precision alterations result from corrosion process, which cannot be found by optical image. The data processing has demonstrated a good correlation between the results obtained by a group of methods at all stages of the corrosion process.