MB8镁合金微弧氧化膜层耐蚀性研究

Study of the corrosion resistance of MB8 Mg alloys by micro-arc oxidation

摘要: 本文采用扫描电镜(SEM)、动电位极化曲线及电化学阻抗(EIS)等测试方法,研究了MB8镁合金微弧氧化后陶瓷膜层的耐蚀性能.结果表明:膜层表面分布着大量相对均匀的放电微孔,孔径在1～3μm之间;膜层分为三层,分别为过渡层、致密层和多孔层,其中致密层占总厚度的60%以上,约6～7μm.动电位极化曲线及电化学交流阻抗测试结果显示微弧氧化处理后镁合金的耐蚀性能得到显著提高.

Abstract: With scanning electron microscopy(SEM),potentiodynamism polarization curves,electronmicroscopy impedance spectroscopy(EIS),corrosion resistance of ceramic coating produced on MB8 magnesium alloy substrates by micro-arc oxidation(MAO) technique had been investigated.The results show that a great deal of comparatively uniform discharge micro-pore whose diameters are 1～3μm are distributed in the surface of film;the oxide coating contains transition layer,compact layer and porous layer,the compactness thickness amounts to 60%,about 6～7μm.Potentiodynamism polarization curves and electrochemical impedance test demonstrate that micro-arc oxidization improves the corrosion resistance of Mg alloys greatly.