Surface charge and corrosion behavior of plasma electrolytic oxidation film on Zr3Al based alloy

The surface charge of Zr3Al based alloy and its plasma electrolytic oxidation (PEO) film were measured in different solutions by streaming current method. Their corrosion property was evaluated by electrochemical impedance spectroscopy (EIS) analysis. The correlation between their surface charge and corrosion behavior was discussed. The results showed that LiCl solution and NaCl solution behaved as inert electrolyte for PEO film. In addition, the low negative zeta potential reduced the adsorption of chloride ions and made the PEO film less susceptible to chloride attack. The PEO film with proper surface charge can also protect Zr3Al alloy from the attack of hydrogen ions and lithium ions.