ZA83镁合金的表面磷化处理

Phosphatization for ZA83 Magnesium Alloy

设计了三种磷化液:基础配方(磷酸盐+高锰酸盐)(1)、基础配方添加氟化钠(2)和基础配方添加柠檬酸(3),并借助金相显微镜、扫描电镜(附有EDXS)及电化学测试系统研究了三种磷化液在ZA83镁合金表面所成磷化膜的组织及耐蚀性。结果表明,3号磷化液的成膜速度相对较快,形成的磷化膜组织较为致密,并且耐腐蚀性能最好,其腐蚀电流密度约比未磷化试样小一个数量级。磷化膜在晶内的厚度大于晶界,其主要组成是Mg、K、Mn的磷酸盐。

Three phosphating solutions were designed,including base formula（phosphate ＋ permanganate）（1）,base formula ＋NaF（2） and base formula ＋ citric acid（3）.The microstructures and anti-corrosive performances of the phosphate coated ZA83 Mg alloy were investigated using optical microscopy,scanning electron microscopy（combined with energy dispersive X-ray spectroscopy（EDXS）） and electrochemical test system.The results show that,solution 1 has advantages over solutions 2 and 3 in phosphating velocity and the compactness of phosphate coatings.The anti-corrosive performance of phosphate coating of solution 3 is the best among the three solutions,and its corrosion electric-current density is smaller than that of the sample without phosphate coating by one order of magnitude or so.The phosphate coating is mainly constituted of phosphates of magnesium,potassium and manganese,and the coating films on the grain boundaries are thinner than these on other regions.