Mg-Zn-Zr-RE合金无铬化学转化膜制备与耐蚀性研究  

Preparation and Studies on Corrosion Resistance of a Non-chromate Conversion Coating for Mg-Zn-Zr-RE Magnesium Alloys

作　　者：朱世凤[1,2] 陈强[1,2] 鲁美琪[1] 陈嫚丽[1,2] 舒大禹[1,2] 邹洪庆[1] 赵祖德[1,2] 

机构地区：[1]中国兵器工业第五九研究所,重庆400039 [2]国防科技工业精密塑性成形技术研究应用中心,重庆400039

出　　处：《表面技术》2011年第6期42-45,共4页Surface Technology

基　　金：国防基础科研重点项目(D1020060945)

摘　　要：采用无铬化学转化方法对镁合金进行表面处理,并用SEM和EDX研究了化学转化膜的表面形貌与组成。研究表明:无铬化学处理溶液为氟钛酸钾与氟锆酸钾6g/L、硝酸钾4g/L、氟酸钾5mL/L及溶液pH值为3;在无铬化学转化处理溶液中添加1.5g/L三聚磷酸铝辅助成膜剂,形成的转化膜层自腐蚀电流密度比镁合金裸材降低了近20倍,自腐蚀电位明显正移;无铬化学转化膜层与传统铬酸盐法形成的转化膜层耐蚀性能相当。Magnesium alloy surface was treated by chemical conversion without chromium. Surface topography and chemical composition of chemical conversion coating were investigated by SEM and EDX. The chemical compositions of liquor prepared by chemical conversion without chromium consisted of 6 g/L mixed liquor （K2TiF6 and K2ZrF6 ） , 4 g/ L nitrate of potassium, 5 mL/L KFO3. The pH value of chemical compositions was 3. Moreover, to improve the properties of film forming, 1.5 g/L aluminum dihydrogen triplyphosphate was also added into the liquor. The results show that self corrosion current density of conversion film prepared by the liquor was decreased to 20 double, compared to that of magnesium alloy. The electric potential of self corrosion current density of conversion film prepared by the liquor obviously moved towards positive electrode. In addition, the corrosion resisting property of membranous layer prepared by chemical conversion without chromium is almost equal to that of membranous layer prepared by conventional chromate.

关 键 词：Mg—Zn-Zr—RE合金 无铬化学转化膜 组成 结构 耐蚀性能 

分 类 号：TG174.45[金属学及工艺—金属表面处理]