电流密度和添加剂对镁合金电化学磷化膜耐蚀性的影响

电化学磷化可以快速获得磷化膜，提高镁合金的耐蚀性，目前就电化学磷化工艺条件对膜层的影响研究尚不深入。为此，采用扫描电镜和电化学方法研究了电流密度和添加剂对镁合金电化学磷化膜耐蚀性的影响。结果显示：电流密度为4．oA／din。时基础磷化液中所得磷化膜表面致密均匀，具有良好的耐蚀性；以0．5g／L酒石酸和5．Og／L磷酸二...

Effects of Current Density and Additives on Corrosion Resistance of Phosphating Coating Prepared on Magnesium Alloy via Electrochemical Route

Phosphating coating was prepared on Mg alloy substrate using an electrochemical phosphating route. The effects of current density and additives on the corrosion resistance of as - obtained phosphating coating were investigated using a scanning electron microscope and an electrochemical test rig.Results show that phosphating coating with compact and uniform surface structure as well as good corrosion resistance can be prepared on Mg alloy substrate by electrochemical phosphating in regular phosphating solution at a current density of 4.0 A/dm~2. Introducing 0.5 g/L tartaric acid and 5.0 g/L sodium dihydrogen phosphate into regular phosphating solution contributed to the accelerated growth of electrochemical phosphating coating on Mg alloy surface and improvement of the compactness and corrosion resistance of the phosphating coating.