钠盐缓蚀剂对镁合金电极电化学性能的影响探究

Influence of Different Sodium Salt Corrosion Inhibitor on Electrochemical Performance of Mg Alloy Electrode

摘要: 采用交流阻抗和电化学恒流放电的方法，探究了不同浓度的钠盐缓蚀剂对AZ31B镁合金在硝酸钾与硝酸钠复合电解液中的耐蚀性和放电行为的影响。实验结果表明，综合考虑阻抗和放电行为，NaHCO₃的最佳浓度为5 mmol/L，(NaPO₃)₆最佳浓度为2 mmol/L。Na₂SiO₃·9H₂O最佳添加浓度为1 mmol/L，此时的滞后时间最短(0.2 s)，激活电位为-2.4 V，极化电阻达到了72 kΩ，耐蚀性也较好。因此，Na₂SiO₃·9H₂O为更优异的缓蚀剂。

Abstract: The electrochemical behavior of magnesium alloy electrodes in composite electrolytes containing different concentrations of sodium salt corrosion inhibitor was investigated. Based on impedance and discharge analysis, the optimal concentration of NaHCO₃ was determined to be 5 mmol/L, while the optimal concentration(NaPO₃)₆ was found to be 2 mmol/L. Addition of 1 mmol of Na₂SiO₃·9H₂O resulted in a negative activation potential (-2.4 V), minimum time lag (0.2 s), and polarization resistance value (R₁) of 72 kΩ, indicating excellent discharge performance and corrosion resistance. Therefore, Na₂SiO₃·9H₂O was proved to be a superior candidate as a corrosion inhibitor.