The Influence of Duration of Polarization Pulses on Structure and Electrochemical Properties of PEO Coating on ML5 Magnesium Alloy

— The influence of various durations of anodic and cathodic polarization during plasma electrolytic oxidation (PEO) is studied. The changes in structure of a protective coating formed on a ML5 foundry magnesium alloy by PEO method are analyzed. We found that the variation in duration of polarization pulses from 50 to 250 μs changes the structure and protective properties. Indeed, the variation in duration of polarization made it possible to change the geometry of pores and their location within the volume of a PEO coating, which had a positive influence on the electrochemical properties. The calculation of consumed electrical energy showed that it is possible to decrease the consumption of electrical energy with a pulse duration of 50 μs, and the protective properties of a PEO coating remain high.