纯镁材微弧氧化膜在硫酸铜溶液中的电化学腐蚀行为  

Electrochemical Corrosion Behavior of Micro-Arc Oxidation Coating on Pure Magnesium in CuSO_4 Aqueous Solution

作　　者：汪翔[1] 马颖[1] 郭惠霞[1] 董海荣[1] 

机构地区：[1]兰州理工大学有色金属先进加工与再利用省部共建国家重点实验室,甘肃兰州730050

出　　处：《材料保护》2015年第12期12-15,6,共4页Materials Protection

基　　金：甘肃省创新研究群体计划(1111RJDA011)资助

摘　　要：研究镁材微弧氧化膜在含Cu2+介质中的腐蚀行为对扩大其使用范围具有十分重要的意义。采用微弧氧化技术对纯镁材进行表面硅酸盐氧化处理,制备了陶瓷膜。采用扫描电镜、X射线衍射、交流阻抗谱等方法分析了微弧氧化膜在0.1 mol/L Cu SO4溶液中的腐蚀形貌、腐蚀产物组成及腐蚀行为;采用极化曲线分析了Cu2+对Cl-腐蚀的影响。结果表明:因为微弧氧化膜中的Mg O与溶液中的H+发生反应,促进了溶液中Cu2+的水解,生成更多Cu(OH)2,并吸附于膜层表面,从而阻止了腐蚀介质向膜基面的进一步扩渗,减弱了腐蚀介质对膜层的腐蚀作用;腐蚀介质Na Cl溶液中加入Cu SO4后,未加剧微弧氧化膜的破坏,反而产生了缓蚀效果。Micro-arc oxidation( MAO) coatings were prepared on pure magnesium by a micro-arc oxidation method. The corrosion morphologies and product composition of MAO coatings in 0. 1 mol / L CuS O4 solution were analyzed by scanning electron microscopy( SEM) and X-ray diffraction( XRD). The electrochemical corrosion behavior of MAO coatings on magnesium in 3. 5% NaC l solution and 0. 1 mol / L CuS O4+ 3. 5% NaC l solution was investigated by electrochemical analysis. Results showed that MgO in MAO coatings reacted with H+of solution to promote the hydrolysis of Cu2 +in solution and created more Cu( OH)2adsorbed on the coating surface,which prevented the aggressive medium from diffusing to the interface of the coating / the substrate,and therefore weakened corrosiveness of the aggressive medium. When CuS O4 was mixed with NaC l corrosive solution,micro-arc oxidation coating on pure magnesium was not destroyed and the corrosion-inhibition effect took place consequently.

关 键 词：纯镁 微弧氧化膜 硫酸铜溶液 腐蚀行为 

分 类 号：TG178[金属学及工艺—金属表面处理]