摘要
研制了钼酸钠添加剂改进磷化膜及钼酸钠、硝酸铈、硅酸钠溶胶封闭后处理改进磷化复合膜,拟替代高毒性铬酸盐钝化膜。采用中性盐雾试验、Tafel极化和电化学阻抗测试对比分析了这4种改进磷化膜与几种传统无铬转化膜、铬酸盐钝化膜耐蚀性的差异;用SEM和EDS研究带划痕试样经盐雾腐蚀后划痕表面的组织形貌和化学成分,初步探讨了改进磷化复合膜的自修复性。结果表明:3种改进磷化复合膜的耐蚀性优于铬酸盐钝化膜,具有自修复作用,有望成为铬酸盐钝化膜的替代品;硅酸钠溶胶封闭后处理改进磷化复合膜的耐蚀性最优。
Several modified phosphate coatings obtained by molybdate additives, molybdate post-sealing, cerium nitrate post-sealing, or silicate sol post-sealing were developed to be as the replacers of high-toxic chromate passivation coatings. The corrosion resistance of four modified phosphate coatings, several chromium-free conversion coatings and chromate passivation coatings was compared using neutral salt spray （NSS） test, Tafel polarization and electrochemical impedance spectroscopy （EIS） measurements. The morphology and chemical compositions of the scratches on three samples with modified composite coatings after NSS test were analyzed using scanning electron microscopy （SEM） and energy dispersive spectroscopy（EDS）. The self-healing performance of the modified composite coatings was discussed preliminarily. The results show that the corrosion resistance of three composite coatings is remarkably superior to that of chromate coatings; Three composite coatings are self-repairable and are the promising replacers of chromate passivation coatings; The anti-corrosion performance of the composite coatings post-sealing with silicate sol is optimal.
出处
《表面技术》
EI
CAS
CSCD
北大核心
2010年第1期37-40,共4页
Surface Technology
关键词
磷化膜
耐蚀性
自修复
铬酸盐钝化膜
Phosphate coatings
Corrosion resistance
Self-repairing
Chromate passivation coatings
