Corrosion and wear resistance of coatings produced on AZ31 Mg alloy by plasma electrolytic oxidation in silicate-based K2TiF6 containing solution: Effect of waveform

In this research, plasma electrolytic oxidation coatings were prepared on AZ31 Mg alloy in a silicate-based solution containing K 2 TiF 6 using bipolar and soft sparking waveforms with 10, 20, 30% cathodic duty cycles. The displayed net-like surface morphology consisted of irregular micro-pores, micro-cracks, fused oxide particles, sintered structure. Due to the incorporation TiO colloidal particles pulse repair effect, most micro-pores sealed. Long-term corrosion performance was investigated electrochemical impedance spectroscopy during immersion 3.5 wt.% NaCl up 14 days. coating grown by waveform 20% cycle having lowest porosity (6.2%) sharp layer concentrated F element at substrate/coating interface shows highest resistance. friction coefficient has remained stable sliding even under 5 N normal load, showing relatively higher wear resistance than other coatings. produced equivalent unipolar waveform, as reference specimen, showed despite its micro-hardness.