为了拓展稀土元素的应用范围,丰富稀土化学转化膜的门类,采用SEM,XPS和EDS等表面分析技术结合电化学分析测试技术,探索在镁合金表面制备新型稀土转化膜——钇盐化学转化膜,分析其形貌、化学组成及耐腐蚀性,并对其成膜机理进行初步的探讨.结果表明,采用文中工艺,可在镁合金表面成功制备覆盖完整具有均匀微裂纹的钇盐化学转化膜.转化膜主要化学组成物组为Y2O3,YOX/Y,MgO和少量的Al2O3.主要成膜元素Y和Mg在膜层与基体界面区域分别呈现递增和递减的现象.电化学测试结果表明,钇盐转化膜可以明显提高镁合金的耐腐蚀性,是一种值得深入发展和研究的新型稀土化学转化膜.
In an effort to expand the application scope of rare earth mineral and at the same time enrich the categories of rare earth chemical conversion coating,a new preparation called yttrium based chemical conversion coating for magnesium alloys study is proposed.The micromorphology,elemental chemical states and corrosion resistance were observed by the surface analysis technologies of SEM,XPS and EDS combined with the electrochemical analysis and testing technology,respectively.The literature review reveals a preliminary study on the new procedure for conversion coating formation mechanism has been done previously.The research results indicate the yttrium-based conversion coating with uniformly distributed micro cracks has formed on the surface of magnesium alloys successfully.The EDS and XPS results reveal,the coating is primarily made of MgO,Y2O3,YOX/Y and a small amount of Al2O3.During the observation of the coating and substrate interface regions,the results suggest,the main two components of the coating had a content increment of element Y and a content decrement of element Mg.The result from the electrochemical analysis and testing proves that yttrium-based conversion coating is a new type of rare earth chemical conversion coating,worthy of developing and studying more intensely,as it can effectively improve the corrosion resistance of magnesium alloys.