Plasma Electrolytic Oxidation Treatment on Magnesium Rare Earth Alloy: Effect of Low Current Density

The poor corrosion resistance of magnesium and its alloys can be overcome by developing appropriate surface treatments of these materials. The article explores the impact of using a current density of 15 mA cm−2, lower than those considered so far for the plasma electrolytic oxidation treatment of the WE43 earth rare-based magnesium alloy, on process energy consumption as well as on microstructure and corrosion properties of oxide coatings grown on the magnesium alloy. Using a low current density during the treatment certainly means significant energy savings, but also good corrosion resistance compared to the untreated alloy, as demonstrated by electrochemical analyses and a through-hole morphology of the oxide coating, which could be useful for all the applications in which beyond good corrosion resistance a specific surface area is essential.