The influence of pulse timing and current mode on the microstructure and corrosion behaviour of a plasma electrolytic oxidation (PEO) coated AM60B magnesium alloy

► PEO was applied to produce oxide coatings on a AM60B alloy. ► Four different current modes namely pulsed unipolar bipolar and hybrid 1 and 2 were used. ► The effects of the negative current part of the pulses on the coating were studied. ► The corrosion protection efficiency of these coatings is compared to those produced by PEO coatings on a AJ62 Mg-alloy.