镁合金微弧氧化复合膜研究进展

微弧氧化（MAO）表面处理技术常用于改善镁合金的特定性能，但MAO膜容易产生微孔和微裂纹从而降低镁合金的耐蚀性。为了提高镁合金微弧氧化膜的使用寿命，主要综述了国内外MAO工艺过程调节措施和MAO膜后处理技术的最新研究进展，重点介绍了近年来国内外镁合金MAO复合膜的研究热点。着重介绍了通过工艺过程调节提高镁合金MAO膜长期保护性能的几项措施：通过电参数和电源类型调节协同电解液成分调整提高MAO膜耐蚀性；通过加入电解液添加剂提高MAO电解液稳定性和电导率；利用具有自封孔作用的添加剂可以参与成膜的特点提高MAO膜致密性；通过复合工艺在MAO膜传统封孔后进一步封闭孔隙。此外，详细介绍了包括疏水涂层、化学镀、类金刚石涂层、生物膜涂层等复合膜工艺的研究进展，强调了复合膜不仅耐蚀性高而且具有功能化应用前景：超疏水复合膜对镁基底具有主动的腐蚀保护作用，超疏水膜协同MAO膜可以提高表面的疏水性；镀镍层致密无微孔且与MAO膜交错咬合能够改善镁MAO膜的导电性和耐蚀性；MAO涂层代替金属缓冲层能够提高类金刚石涂层和基体界面结合强度；生物复合涂层不仅耐蚀性高还具有促进细胞增殖和分化生物活性的作用。最后，基于镁...

Research Progress of Micro-arc Oxidation Composite Films for Magnesium Alloys

Micro-arc oxidation (MAO) surface treatment is often used to improve specific properties of magnesium alloys, but MAO films tend to produce micropores and microcracks, which deteriorate corrosion resistance of magnesium alloy. In order to improve the service life of magnesium alloy micro-arc oxidation (MAO) film, the latest research progress of MAO process adjustment measures and MAO film post-treatment technology at home and abroad was reviewed, and the research hotspot of MAO composite film at home and abroad in recent years was mainly introduced. Several measures to improve the long-term protection performance of magnesium alloy MAO film by process adjustment were mainly summarized. The adjustment of electrical parameters and power supply type combined with the adjustment of electrolyte composition can improve the corrosion resistance of MAO film. Adding additives into the electrolyte can improve the stability and conductivity of MAO electrolyte. Adding self-sealing hole additives can participate in the film formation to improve the compactness of MAO film. The pores were further sealed by composite process after traditional pore-sealing for MAO film. Furthermore, the research progress of composite coating technology was introduced in detail, including the hydrophobic coatings, electroless plating, diamond-like coating and biological membrane coating. It is emphasized that the composite film not only had high corrosion resistance but also had the prospect of functional application. Super hydrophobic composite film had active corrosion protection effect on magnesium substrate, so it can assist MAO film to improve the surface hydrophobicity. The nickel plating layer was compact and has no micropores, improving the conductivity and corrosion resistance of magnesium MAO film by cross bite with MAO film. MAO coating replaced the metal buffer layer to improve the interface bonding strength between diamond-like coating and matrix. The biological composite coating not only had high corrosion resistance but also had biological activity to promote cell proliferation and differentiation. Finally, based on the research status of MAO process of magnesium alloy, the future development trend of MAO composite film was prospected.