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为了研究添加Al_2O_3微粉对AZ31A镁合金微弧氧化膜特性影响,在不同浓度Al_2O_3微粉氧化液中对其进行了微弧氧化处理。利用扫描电镜(SEM)观察了微弧氧化膜形貌,能谱仪(EDS)分析了膜层表面Ca、Mg、O、Al元素分布,X射线衍射仪(XRD)分析了相组成,测定了膜厚、硬度和氧化液中Al_2O_3表面电荷,讨论了改性机理。结果表明,加入Al_2O_3微粉后,氧化电压随Al_2O_3添加量增加先增加后降低;氧化膜表面孔洞数量和尺寸减小,膜层表面Ca元素分布逐渐减少,成膜效率降低,膜层致密度和表面疏松层硬度提高,氧化膜主要由MgO和MgO_4等相组成。
In order to study the effect of adding Al 2 O 3 micropowder on the micro-arc oxidation film properties of AZ31A magnesium alloy, micro-arc oxidation treatment was carried out in different concentrations of Al 2 O 3 micropowder oxidation solution. The morphology of MAO coatings was observed by scanning electron microscopy (SEM). The distributions of Ca, Mg, O and Al on the surface of coatings were analyzed by energy dispersive spectroscopy (EDS). The phase composition was analyzed by XRD. Film thickness, hardness and surface charge of Al 2 O 3 in oxidizing solution, the modification mechanism was discussed. The results show that with the addition of Al 2 O 3, the oxidation voltage first increases and then decreases with the increase of Al 2 O 3 addition. The number and size of pores in the oxide film decrease, the distribution of Ca in the film gradually decreases, the film formation efficiency decreases, the film density and the surface Loose layer hardness increases, the oxide film is mainly composed of MgO and MgO 4 phases.