磷酸一氢钠对AZ91镁合金的缓蚀作用

Corrosion Inhibition of Disodium Hydrogen Phosphate for AZ91 Mg Alloy

采用电化学阻抗谱(EIS)、动电位极化曲线、失重法和扫描电镜研究了磷酸一氢钠对AZ91镁合金在0.05%NaCl溶液中的缓蚀行为,及其与部分有机物的协同作用。结果表明,因为磷酸一氢根离子与镁离子反应产生了镁盐沉淀物,磷酸一氢钠对镁合金有一定的缓蚀作用;有机磺酸盐、羧酸盐或氨酸盐单独使用时,这些缓蚀剂的阴离子可以部分吸附在镁合金表面上,从而起到一定程度的保护作用;磷酸一氢钠与磺酸盐复配使用时缓蚀效率最高。

Electrochemical impedance spectroscopy, potentiodynamic pol;irization curves, weight loss and scanning electron microscopy were used to study the inhibition behavior of disodium hydrogen phosphate for AZ91 Mg alloy in 0. 05G NaCl solution. The results indicated that the mono;hydrogen phosphate can inhibit the corrosion of AZ91 Mg alloy effectively, because the deposits of magnesium salt protect the alloy surface from corrosion. When organic sulfonate or carboxylate was used alone, their anions adsorbed on the surface of Mg alloy, and thus protected Mg alloy to a certain extent. When they compounded with mono-hydrogen phosphate, they can improve the inhibition efficiency of mono-hydrogen phosphate, and the maximum inhibition rate can be reached by sutfonate compounded with mono-hydrogen phosphate.