IMPROVEMENT IN CORROSION AND WEAR RESISTANCE OF GLASS-SEALED PEO COATING ON THE AZ31B MAGNESIUM ALLOY

Magnesium alloys are prone to corrosion, limiting their applications as biodegradable implants because of their poor corrosion and wear resistance in corrosive environments. This study investigates the effect of the incorporation of pulverized glass nanoparticles during the Plasma Electrolytic Oxidation (PEO) process to improve the mechanical performance of the AZ31B Mg alloys. The surface morphology and composition were analyzed through the SEM and EDS mapping, which confirmed a denser, homogeneous coating. The Potentiodynamic Polarization (PDP) characterization in 3.5[Formula: see text]wt.% NaCl solution showed that the corrosion current density of the bare Mg alloy reduces from [Formula: see text] [Formula: see text]A/cm 2 to [Formula: see text] [Formula: see text]A/cm 2 for the glass-added PEO layer. The glass-filled PEO layer possesses a polarization resistance three orders of magnitude higher than that of the bare Mg substrate. Electrochemical Impedance Spectroscopy (EIS) analysis revealed a suppressed inductive response, near capacitive behavior, and higher impedance values (95–113[Formula: see text]k[Formula: see text].cm 2 ) of the glass-filled PEO coating, ensuring the corrosion resistance of the glass-filled inner barrier layer and reducing the pitting corrosion. Meanwhile, the hardness of the bare sample increases from 58[Formula: see text]HV to 245[Formula: see text]HV for the glass-free PEO layer and further increases to 335[Formula: see text]HV for the glass-incorporated PEO coating. The wear rate decreased to ([Formula: see text])[Formula: see text] × [Formula: see text]10[Formula: see text] [Formula: see text]mm 3 /Nm (two orders lower than the bare Mg substrate) and exhibited the lowest coefficient of friction. Thus, it can be inferred that incorporating nano-glass particles into the PEO layer is a promising approach for improving the corrosion and wear resistance of AZ31B magnesium alloy for the application of biodegradable implants.