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采用电化学测试(极化曲线,开路点位,电化学阻抗谱)研究了Mg-3Zn-0.5Zr合金在4种侵蚀性离子(Cl~-,HPO_4~(2-),HCO_3~-和SO_4~(2-))相互作用下的降解行为。发现Cl-会导致合金发生多孔状点蚀,腐蚀坑在表面扩展并加深。HPO_4~(2-)能降低合金降解速率抑制点蚀。HCO_3~-离子早期大大加快了镁合金的腐蚀降解速率,但由于能够在剧烈腐蚀部位诱导钝化,对合金点蚀的扩展具有抑制作用。SO_4~(2-)在生理环境中浓度低,所以对合金腐蚀降解的行为加速不明显。
The effects of Mg-3Zn-0.5Zr alloy on four kinds of aggressive ions (Cl ~ -, HPO_4 ~ (2 -), HCO_3 ~ - and SO_4) were studied by means of electrochemical tests (polarization curves, open circuit sites and electrochemical impedance spectroscopy) ~ (2-)) interaction. Cl- was found to cause porous pitting corrosion of the alloy, corrosion pits on the surface to expand and deepen. HPO_4 ~ (2-) can reduce the rate of alloy degradation and inhibit pitting corrosion. In the early stage of HCO 3 ~ - ion, the corrosion rate of magnesium alloy was accelerated greatly. However, due to its ability to induce passivation in severe corrosion sites, the inhibition of pitting corrosion was inhibited. SO_4 ~ (2-) concentration in the physiological environment is low, so the degradation of the alloy corrosion behavior is not obvious.