AZ31B镁合金表面微弧电泳复合膜层微观结构及耐蚀性表征

发布时间：2018-01-20 05:31

本文关键词： 镁合金微弧氧化电泳复合膜层耐蚀性　出处：《稀有金属材料与工程》2015年07期 　论文类型：期刊论文

【摘要】：采用微弧氧化技术在AZ31B镁合金表面制备陶瓷层,利用其表面多孔结构借助电泳技术沉积有机膜层,对比研究陶瓷层和复合膜层表面粗糙度、表面及截面形貌、电化学性能及划伤腐蚀特性。结果表明:陶瓷层表面放电微孔被电泳层完全填充并形成均匀膜层,复合膜层表面粗糙度明显降低;微弧电泳复合膜层腐蚀电流密度与陶瓷层和基体相比分别降低2个和4个数量级,极化电阻分别增大2个和4个数量级,腐蚀倾向降低;微弧电泳复合膜层电化学阻值与陶瓷层相比增加4个数量级,同时电容值降低4个数量级,耐蚀性显著提高;由于陶瓷层与电泳层的机械嵌合作用,复合膜层划伤腐蚀过程表现为基体腐蚀及陶瓷层与基体界面的破坏,复合膜层界面处结合完好。
[Abstract]:Ceramic layer was prepared on the surface of AZ31B magnesium alloy by micro-arc oxidation technology. The surface roughness of ceramic layer and composite film was compared by electrophoretic deposition with porous structure. The results showed that the ceramic layer was completely filled with electrophoretic layer and formed a uniform film, and the surface roughness of the composite film decreased obviously. Compared with ceramic layer and substrate, the corrosion current density of the composite film decreased by 2 and 4 orders of magnitude, the polarization resistance increased by 2 and 4 orders of magnitude, and the corrosion tendency decreased. Compared with the ceramic layer, the electrochemical resistance of the composite film increased by 4 orders of magnitude, while the capacitance value decreased by 4 orders of magnitude, and the corrosion resistance of the composite film increased significantly. Because of the mechanical chimerism between the ceramic layer and the electrophoretic layer, the scratching corrosion process of the composite film is as follows: substrate corrosion and the destruction of the interface between the ceramic layer and the substrate, and the interface of the composite film is well bonded.
【作者单位】：西安理工大学;南京工业大学;
【基金】：国家自然科学基金(51271144) “十二五”国家科技支撑计划(2011BAE22B05)
【分类号】：TG174.4
【正文快照】： 电泳涂装具有膜层均匀、色泽稳定以及化学惰性强等特点,可有效隔离基体与服役环境,是一种较为理想的表面防护技术,在钢铁和铝合金制品表面改性处理已获得广泛应用[1,2]。但由于镁合金基体表面形成疏松的氧化膜导致电泳处理后基体与有机膜层的结合较差,很难起到防护作用,严重制

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