二次电压对AZ91D镁合金微弧氧化封孔的影响

发布时间：2018-04-14 15:09

本文选题：镁合金 + 微弧氧化　；参考：《表面技术》2017年05期

【摘要】：目的提高镁合金微弧氧化膜层的耐蚀性。方法在锆盐体系电解液中对AZ91D镁合金进行微弧氧化处理,通过调节二次电压对AZ91D镁合金微弧氧化膜层的孔隙进行封闭,采用XRD、SEM和电化学测试分别对微弧氧化膜层的物相、表面形貌和耐蚀性进行了研究。结果二次电压对膜层的相成分没有影响,主要相组成为MgO、MgF_2、ZrO_2、Mg_2Zr_5O_(12)。随着二次电压的升高,膜层表面放电微孔孔径先减小后增大,孔隙率先降低后升高。与没有二次电压相比,施加二次电压的腐蚀电流降低2~3个数量级,极化电阻升高1~2个数量级,耐蚀性明显提高,且当二次电压为160 V时,膜层的极化电阻最高,耐蚀性最好。结论二次电压能够对AZ91D镁合金微弧氧化膜层的孔隙进行封闭,进而阻止腐蚀液通过微孔进入基体,提高膜层的耐蚀性。
[Abstract]:Objective to improve the corrosion resistance of magnesium alloy microarc oxide film.Methods AZ91D magnesium alloy was treated by micro-arc oxidation in zirconium salt electrolyte. The pore of AZ91D magnesium alloy micro-arc oxide film was sealed by adjusting the secondary voltage.The surface morphology and corrosion resistance were studied.Results the secondary voltage has no effect on the phase composition of the film, and the main phase composition is MgO / MgF _ 2ZR _ 2O _ 2J _ 2O _ 2J _ 2Zr _ 5O _ s _ 2.With the increase of secondary voltage, the pore size of discharge micropore on the surface of the film decreases first and then increases, and the pore size decreases first and then increases.Compared with no secondary voltage, the corrosion current applied to the secondary voltage is reduced by 2 ~ 3 orders of magnitude, the polarization resistance is increased by 1 ~ 2 orders of magnitude, and the corrosion resistance is obviously improved. When the secondary voltage is 160 V, the polarization resistance of the film is the highest and the corrosion resistance is the best.Conclusion the secondary voltage can seal the pores of the AZ91D magnesium alloy micro-arc oxide film, and then prevent the corrosion solution from entering into the substrate through the micropore, and improve the corrosion resistance of the film.
【作者单位】：长安大学;
【基金】：国家自然科学基金资助(51301022) 陕西省自然科学基金(2016JQ5032)~~
【分类号】：TG174.44

【参考文献】