电解液中CeO_(2)/Y_(2)O_(3)浓度对2A12铝合金微弧氧化膜耐蚀性的影响研究

Effect of CeO_(2)/Y_(2)O_(3) Concentration in the Electrolyte on Corrosion Resistance of 2A12 Aluminum Alloy Micro Arc Oxidation Film

采用扫描电镜(SEM)、X射线衍射仪(XRD)和电化学技术研究了电解液中CeO_(2)/Y_(2)O_(3)浓度对2A12铝合金微弧氧化膜耐蚀性的影响。结果表明,随着CeO_(2)/Y_(2)O_(3)稀土氧化物浓度的增加,微弧氧化膜中γ-Al_(2)O_(3)的含量先出现增大,膜层开始变得光滑,微孔数量出现减小,裂纹逐渐消失,膜层的I_(corr)减小,容抗弧扩大,耐蚀性逐渐提升;当浓度大于3 g/L后,弧光放电变得激烈,氧化膜中γ-Al_(2)O_(3)的含量反而逐渐降低,孔洞数量增加,孔径增大,膜层的I_(corr)增大,容抗弧收缩,耐蚀性下降。

The effects of CeO_(2)/Y_(2)O_(3) concentration in the electrolyte on corrosion resistance of 2A12 aluminum alloy micro arc oxidation film were studied by using scanning electron microscope(SEM), X-ray diffraction(XRD) and electrochemical techniques. The results show that, with the increase of CeO_(2)/Y_(2)O_(3) rare earth oxide concentration in the electrolyte, the content of γ-Al_(2)O_(3) in MAO film increased, the MAO film became smooth, the number of micropores decreased and the cracks disappeared in the MAO film, the Icorr decreased, the capacitance arc was enlarged and the corrosion resistance was improved gradually. When the concentration was beyond 3 g/L, with the increase of CeO_(2)/Y_(2)O_(3) concentration, the arc discharge becames intense, the content of γ-Al_(2)O_(3) in MAO film gradually decreased, the number and size of hole increased in the MAO film, the I_(corr) increased, the capacitance arc shrinked and the corrosion resistance decreased gradually.