Fig. 8. Polarization curves in SBF solution at 37 °C and ML324 of 7.4 for the (a) substrate and anodized samples at (b) 20 V, (c) 50 V.Figure optionsDownload full-size imageDownload as PowerPoint slide
Analysis results of potentiodynamic polarization curves (in SBF solution at 37 °C and pH 7.4).SampleEcorr (V) Mean± SDIcorr (µA/cm2)AZ31B-Control−1.46±0.0162.796±1.5420 V−1.41±0.0063.17±0.0850 V−1.38±0.0471.9±1.54Full-size tableTable optionsView in workspaceDownload as CSV
An increase of the anodic potential during the test results in the substrate reacting with chloride ions from the SBF solution, and MgCl2 is produced while pit formation occurs . The main purpose of samples anodization is to produce a protective film which can block chloride and corrosive ions to penetrate into the substrate and to control the degradation process . The results show that both anodized samples were shifted towards the noble direction, as shown in Fig. 8 and summarized results in Table 2. Anodization at 50 V exhibits the highest potential resistance subsequently, more corrosion resistant resulted, fontanels can indicate that adding ZrO2-NPs could improve and control the corrosion behavior of the AZ31B magnesium alloy .