Fe盐掺杂镁合金微弧氧化膜的性能

Properties of Micro-Arc Oxidation Coating Doped Ferric Citrate on Magnesium Alloys

为满足航天器电子结构产品对热控、防腐蚀功能的需求,采用Fe盐对镁合金微弧氧化膜层进行掺杂改性。采用扫描电镜、X射线衍射仪辐射计及极化曲线研究了Fe盐对微弧氧化膜层微观形貌、热控性能以及耐蚀性的影响。结果表明:镁合金微狐氧化膜层经Fe盐改性掺杂后,膜层微观孔径增大,外观为灰黑色至黑色;Fe盐以氧化物的形式均匀掺杂到膜层中;膜层经掺杂改性后,半球发射率由0.73提高至0.85以上,热控性能显著提高,而耐蚀性能较未掺杂膜层略有下降。

Micro-arc oxidation（MAO） coatings on magnesium alloys were modified by doping ferric citrate. The scanning electron microscope, X-ray diffraetometer, and polarization curves were employed to study the influence of ferric citrate on the micro- morphology, thermal control performance and corrosion resistance of MAO coating. Results showed that after modified with ferric citrate, the MAO coating on Mg alloy pos- sessed micro-pores of lager size, and the appearance changed from taupe to black. Fe element was in the form of oxide state, uniformly distrib- uted in the coating. Furthermore, after modifying treatment, the hemispherical emissivity of coating was improved from 0.73 to 0.85, which in- dicated that the thermal control property was increased significantly. Compare with the MAO coating without ferric salt, the corrosion resistance of modified coating declined slightly.