电流密度对镁合金微弧氧化膜性能的影响

Effect of current density on the properties of microarc oxidation coatings on Mg alloys

微弧氧化技术是一种工艺简单、高效和环保的镁合金表面处理技术。利用涡流测厚仪、光学显微镜、激光共聚焦显微镜、点滴实验和盐雾腐蚀的方法研究电流密度对镁合金微弧氧化膜的厚度、微观组织和耐蚀性能等的影响。结果表明:电流密度越高,微弧氧化膜表面微孔的孔径越大,且膜层生长速率呈线性上升趋势。当电流密度为5.6A/dm2时膜层的耐蚀性最好。

Microarc oxidation （MAO） processing is a simple, high-efficient and environmentally friendly technique for the surface treatment of a magnesium alloy. The influences of current density on thickness, microstructure and corrosion resistance of magnesium MAO coatings are studied by the methods of eddy thickness meter, the optical microscope, laser confocal microscope, drop experiment and salt fog corrosion. The results show that both the diameter of micropoles on the MAO coatings and the growth rate increase linearly with the increasing of current density. When the current density is 5.6 A/dm^2, the corrosion resistance of the coating is the best.