Abstract

Effects of the sodium borate concentrations in NaOH-Na₂SiO₃-Na₂B₄O₇ electrolytes on the surface and corrosion properties of plasma electrolytic oxidation (PEO) coatings on AZ31 Mg alloy were investigated. Characteristics of PEO coatings were examined by scanning electron microscopy, X-ray diffraction, potentiodynamic polarization and electrochemical impedance spectroscopy. It was found that the corrosion resistance of the Mg alloy was remarkably improved via PEO treatment with the 3 g/L of sodium borate content in the electrolyte, resulting from relatively less porous morphology of PEO coating. Thus, the incorporation of sodium borate in the electrolytes can be provided an effective barrier to enhance corrosion resistance of the PEO coating on AZ31 Mg alloy.

摘要

_{NaOH-Na 2} SiO ₃ -Na ₂ B ₄ O ₇中硼酸钠浓度的影响研究了 AZ31 镁合金表面的电解质和等离子电解氧化 (PEO) 涂层的腐蚀性能。通过扫描电子显微镜、X射线衍射、动电位极化和电化学阻抗谱检查PEO涂层的特性。结果表明，在电解液中硼酸钠含量为 3 g/L 的情况下，通过 PEO 处理，镁合金的耐腐蚀性能得到显着提高，这是由于 PEO 涂层的多孔形态相对较少。因此，在电解质中掺入硼酸钠可以提供有效的屏障，以增强 AZ31 镁合金上 PEO 涂层的耐腐蚀性。