AZ91D镁合金恒功率微弧氧化膜的结构及耐蚀性能

发布时间：2018-09-05 09:32

【摘要】：目前,对镁合金表面恒功率微弧氧化的研究尚不够深入。在Na2Si O3-Na OH体系中,通过恒功率控制微弧氧化,在AZ91D镁合金表面获得了微弧氧化膜。分别利用SEM,EDS,XRD,硫酸铜点滴及Na Cl浸泡腐蚀等方法分析了微弧氧化膜的形貌、成分、结构及耐蚀性能。结果表明:恒功率制备的微弧氧化膜由Mg,O,Si,Al元素组成,其物相主要由Mg,Mg O,Mg2Si O4组成;在1~3 k W功率内,随着功率的增加,膜层表面微孔数量减少,孔径增大,在含Cl-溶液中的耐腐蚀性能变差;与恒压控制相比,恒功率控制使得镁合金微弧氧化初期在大电流下起弧,而后期是在高电压环境下进行,导致所形成的微弧氧化膜具有较少的微孔,但具有较大的孔径和较快的生长速度。
[Abstract]:At present, the research on surface constant power micro-arc oxidation of magnesium alloy is not enough. Microarc oxidation films were obtained on the surface of AZ91D magnesium alloys by constant power controlled microarc oxidation in Na2Si O3-Na OH system. The morphology, composition, structure and corrosion resistance of the micro-arc oxide film were analyzed by SEM,EDS,XRD, copper sulfate drop and Na Cl immersion corrosion. The results show that the micro-arc oxide films prepared at constant power are composed of Mg,O,Si,Al elements, and the phase is mainly composed of Mg,Mg O _ 2O _ (mg _ 2SiO _ 4), and the number of micropores on the surface decreases and the pore size increases with the increase of power at 1kW power. Compared with constant voltage control, constant power control makes magnesium alloy micro-arc oxidation start at high current at the initial stage, and then under the high voltage environment at the later stage, the corrosion resistance of magnesium alloy in the solution containing Cl- becomes worse, and compared with the constant voltage control, the micro-arc oxidation of magnesium alloy is carried out at the beginning of the arc oxidation process. The resulting micro-arc oxide film has less micropores, but larger pore size and faster growth rate.
【作者单位】：四川理工学院材料与化学工程学院;四川理工学院材料腐蚀与防护四川省重点实验室;
【基金】：材料腐蚀与防护四川省重点实验室开放基金(2013CL01) 四川理工学院大学生创新基金(201410622022)资助
【分类号】：TG174.4

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