磷化液组分对铝合金磷化膜耐蚀性能的影响

摘要

The electrochemical behavior of zinc phosphating coating on LY12 aluminum alloy was studied by electrochemical tests. The influence of Zn(H2PO4)2 · 2H2O, Zn(NO3)2 · 6H2O, NaClO3 and NaF content on the electrochemical properties of zinc phosphating coating was determined. The results showed that under the combination of Zn(H2PO4)2 · 2H2O 10g/L, Zn(NO3)2 · 6H2O 35g/L, NaClO3 2g/L and NaF 3 g/L the phosphating coating has the maximum corrosion potential and linear polarization resistance, minimum corrsoion current density and the best corrosion resistance.%采用电化学测试方法对LY12铝合金的锌系磷化膜的电化学性能进行研究.分别讨论了磷化液中磷酸二氢锌、硝酸锌、氯酸钠及氟化钠质量浓度的变化对磷化膜电化学性能的影响.结果表明,当溶液组成为10g/L磷酸二氢锌、35g/L硝酸锌、2g/L氯酸钠、3g/L氟化钠时,铝合金磷化膜的腐蚀电位最大,腐蚀电流最小,线性极化电阻最大,耐蚀性最好.