阴极极化法制备AZ91D表面铈转化膜的研究

Investigation of Preparation of Ce Conversion Coatings on AZ91D Magnesium Alloy by Using Potentiostatic Technique

应用阴极极化技术在AZ91D镁合金表面形成铈盐转化膜,研究了转化膜的腐蚀防护作用.腐蚀行为的测试是将阴极极化成膜试样、浸泡转化成膜试样和基体在3.5%NaCl溶液中进行动电位极化测试,结果表明:阴极极化铈盐转化成膜处理可使合金的腐蚀电位正移,出现钝化现象,自腐蚀电流密度明显降低,阴极转化成膜可以对AZ91D镁合金起到理想的防护作用.

The deposition of Ce chemical conversion coatings on AZ91D magnesium alloy by using the potentiostatic technique was investigated to improve uniformity and corrosion protection performance of the coating film. The corrosion behavior of the specimens with and without conversion film was investigated by the methods of potentiodynamic polarization in 3.5wt% neutral NaCl solution. The results show that the corrosion potential increased and passive phenomenon exists while the current density decreases. The film formed by using the potentiostatic technique can provide good protection to the AZ91D alloy.