不同电压下CrO_3对镁合金微弧氧化膜的影响  

Effect of chromium trioxide with different applied voltages on micro-arc oxide film on magnesium alloy

作　　者：马颖[1] 王宇顺[1] 王劲松[1] 董海荣[1] 郭惠霞[1] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料重点实验室,甘肃兰州730050

出　　处：《兰州理工大学学报》2011年第4期1-5,共5页Journal of Lanzhou University of Technology

基　　金：国家重点基础研究发展计划资助(2007CB613700);人社部留学人员科技活动择优资助

摘　　要：在硅酸盐体系电解液中加入CrO3制备微弧氧化膜,并研究不同电压下CrO3对AZ91D镁合金微弧氧化膜的影响.结果表明:硅酸盐系电解液中CrO3的加入使膜层中生成新的物相MgCr2O4,该物相具有尖晶石结构,有利于提高膜层的耐蚀性,且CrO3加入后获得绿色的微弧氧化膜,其中起显色作用的物质就是MgCr2O4.随着CrO3含量的增加,膜层的厚度变化不明显,只是膜层颜色逐渐加深,然而CrO3微小的添加量对膜层耐蚀性的提高有显著贡献,其添加量无需超过0.3g/L.在高电压、较高的成膜速率条件下可以获得比低电压更厚的微弧氧化膜层,并且高电压下所获得膜层具有良好的耐蚀性,这主要源自于较大的膜层厚度、较低的表面孔隙率.Micro-arc oxide film was prepared by using silicate-system electrolyte with CrO3 addition and the effect of chromium trioxideou micro-arc oxide film（MAO） on AZ91D magnesium alloys was investigated.The result showed that a new phase of MgCr2O4 with spinel structure was obtained in MAO film due to the addition of CrO3 into the electrolyte.The new phase was beneficial to the corrosion resistance of the film.And MAO film was of green color,which was also attributed to the existence of MgCr2O4 phase in the film.With the increasing of the concentration of chromium trioxide,the changing of film thickness was not obvious but its green color was gradually deepened.However,the corrosion resistance of the film was significantly improved with a little addition of CrO3 that did not exceed 0.3 g/L in the solution.The much thicker MAO film could be obtained with a higher voltage than that under the lower voltage due to a faster growing rate of the film.The thicker the film thickness and the lower the surface porosity were,the better corrosion resistance could be gained with higher applied voltage.

关 键 词：AZ91D镁合金 微弧氧化着色 CRO3 耐蚀性 

分 类 号：TG174[金属学及工艺—金属表面处理]