【摘要】 采用SEM、XRD、动电位极化曲线及电化学阻抗等测试方法,研究了MB8镁合金微弧氧化过程中不同终止电压下获得的陶瓷膜层的耐蚀性能。结果表明:终止电压越高,膜层越厚;微火花阶段,膜层表面均匀、结晶细致,腐蚀电流密度较小,阻抗较大;弧放电阶段,膜层孔径变大,陶瓷层内显微缺陷增多,腐蚀电流密度增大,阻抗减小。由此得出结论:膜层耐蚀性能由膜层厚度与终止电压共同决定,微火花放电末期膜层的耐蚀性能优于弧放电阶段的耐蚀性能。更多还原

【Abstract】 With scanning electron microscopy(SEM),X-ray Diffraction(XRD),potentiodynamism polarization curves,electronmicroscopy impeclance spectroscopy(EIS),corrosion resistance of membrane produced at different final voltage on MB8 magnesium alloy substrates by micro-arc oxidation (MAO) technique had been investigated.The results show: the higher the final voltage,the thicker the membrane;micro sparking oxide coating exhibites better performance of compact,homogeneous and high resistance comparing with arc-oxide coatings in which pore diameter augment and micro-defect multiply of ceramic coatings.Thereby comes to the conclusion that the membrane level erosion codetermines with membrane thickness and final voltage,the erosion of membrane at micro spark discharge last stage excels than arc discharge membrane.更多还原