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采用极化曲线分析、电化学阻抗谱(EIS)测试和浸泡实验的方法,并结合XPS,XRD和SEM等分析手段对新型医用Ti-24Nb-4Zr-8Sn合金在37℃的Hanks人工模拟体液中的电化学腐蚀行为进行了研究,并与纯Ti和Ti-6Al-4V合金进行了比较.结果表明:在37℃的Hanks溶液中,Ti-24Nb-4Zr-8Sn合金的腐蚀电流密度与纯Ti相等,并且钝化性能优于纯Ti和Ti-6Al-4V,这与其钝化膜中存在大量的Nb_2O_5密切相关;EIS结果显示,Ti-24Nb-4Zr-8Sn合金表面形成内层致密而外层疏松的双层钝化膜结构,致密层特性对材料的耐蚀性能起到决定性作用;随着浸泡时间的延长,致密内层的电阻大幅度提高,Ti-24Nb-4Zr-8Sn合金的耐蚀性能增强,同时疏松外层中的微缺陷发展成为宏观裂纹,造成疏松外层整体脱落.
Polarization curve analysis, electrochemical impedance spectroscopy (EIS) and immersion experiments were carried out on the new medical Ti-24Nb-4Zr-8Sn alloy in Hanks artificial simulated body fluid at 37 ℃ by means of XPS, XRD and SEM. The electrochemical corrosion behavior of Ti-24Nb-4Zr-8Sn alloy was studied and compared with pure Ti and Ti-6Al-4V alloy.The results show that the corrosion current density of Ti-24Nb-4Zr- The results of EIS show that the surface of Ti-24Nb-4Zr-8Sn alloy has a dense inner layer and the outer layer of Ti-24Nb-4Zr- Loose double-layer passivation film structure, the characteristics of the dense layer plays a decisive role on the corrosion resistance of the material; With the extension of immersion time, the resistance of the dense inner layer greatly increased, the corrosion resistance of Ti-24Nb-4Zr-8Sn alloy Performance enhancement, while loose outer defects in the development of micro-cracks into a macro, resulting in loose outer overall shedding.