AZ31镁合金阳极氧化工艺参数的优化研究

摘要

The technological parameters for anodizing AZ 31 magnesium alloy in alkaline electrolyte were optimized by orthogonal experiment. The effects of anodizing time, current density, pulse frequency and duty ratio on the properties of the anodized film were studied, obtaining an optimal anodizing process; anodizing time 15 min, current density 1.0 A/dm2, pulse frequency 200 Hz and duty ratio 10 % . The phase composition, surface morphology and corrosion resistance of the anodized film were investigated respectively by XRD, SEM and potentiodynamic polarization curves. It is shown that the anodized film obtained by the optimized process is mainly composed of MgO, Al2O3 and MgAl2O4 , which is compact and uniform in pore distribution, resulting in an improved corrosion resistance.%采用正交实验对AZ 31镁合金在碱性电解液中进行阳极氧化的工艺参数进行优化.考察了氧化时间、电流密度、脉冲频率和占空比对阳极氧化膜性能的影响,获得最佳阳极氧化工艺参数为:氧化时间15 min,电流密度1.0 A/dm2,脉冲频率200 Hz,占空比10％.采用X射线衍射仪(XRD)、扫描电镜(SEM)和动电位极化曲线等检测手段研究了阳极氧化膜的结构、表面形貌和耐蚀性.结果表明:经优化工艺制得的阳极氧化膜,其主要成分为MgO,Al2O3和MgAl2O4,膜层孔隙分布均匀、致密,耐蚀性大幅提高.