Quasi-in vivo corrosion behavior of AZ31B Mg alloy with hybrid MWCNTs-PEO/PCL based coatings

This study investigated the effects of multi-walled carbon nanotubes (MWCNTs) and polycaprolactone (PCL) on quasi-in vivo corrosion behavior AZ31B Mg alloy treated by plasma electrolytic oxidation (PEO). Thin (∼2 µm, PCTPCL4) thick (∼60 PCTPCL6) PCL layers were applied only onto MWCNTs-PEO coating (PCT) as it showed better performance. Findings reveal that incorporation MWCNTs induced several structural functional modifications in PEO coating, such increased roughness, a thicker inner barrier layer, reduced hydrophilicity. Quasi-in testing was carried out under controlled temperature, pH, fluid flow simulated body (SBF) electrochemical impedance spectroscopy (EIS) hydrogen evolution experiments. EIS results revealed that, after 48 h immersion, diffusion process hydration ceramic coatings. Comparison collected 15 days immersion environment PCT coatings decreased generation up to 74% 91%, respectively, compared non-coated alloy. PCTPCL6 exhibited lowest amount (0.2 mL/cm2). The layer delayed onset substrate for at least 120 h, reducing rate 85% with PCT.