LZ91合金板材微弧氧化复合膜层的腐蚀行为

Corrosion Behavior of Micro-arc Oxidation Composite Coating on LZ91 Magnesium Alloy

在含有石墨烯电解液中对LZ91镁锂合金板材进行微弧氧化处理,获得微弧氧化(MAO)膜层,通过浸入法在MAO膜层上分别制备出双层导电膜层(MAO/CG)和三层防腐膜层(MAO/CG/AG)。利用金相显微镜和扫描电镜观察微观形貌,通过电化学工作站分析膜层腐蚀行为,利用霍尔效应测量膜层电导率。结果表明,当电解液中石墨烯浓度为1.0 g/L时,制备的MAO膜层腐蚀为0.13 mm/a;MAO/CG双层导电膜层的腐蚀速率为0.04 mm/a,霍尔效应电导率为7.89 S/cm;MAO/CG/AG三层防腐膜层的腐蚀速率为0.003 mm/a。

LZ91 magnesium lithium alloy sheet was microarc oxided in graphene electrolyte to obtain MAO film layer.A double-layer conductive film(MAO/CG)and a triple-layer anti-corrosion film(MAO/CG/AG)were prepared on the MAO film layer by immersion method.The micro morphology was observed by metallographic microscopy and scanning electron microscopy,and the corrosion behaviour of the film layers was analyzed by electrochemical workstation,and the electrical conductivity of the film layers was measured using the Hall effect.The results reveal that the minimum corrosion rate of prepared MAO film layer is 0.13 mm/a when the concentration of graphene in the electrolyte is 1.0 g/L,while that of MAO/CG double-layer conductive film layer is 0.04 mm/a and the Hall effect conductivity is 7.89 S/cm.In addition,the MAO/CG/AG triple-layer anticorrosive film layer has corrosion rate of 0.003 mm/a.