(中国科学院 金属研究所 沈阳材料科学国家(联合)实验室，沈阳 110016)
摘 要: 研究了经冷轧纳米化处理的医用Ti-24Nb-4Zr-8Sn纳米晶合金(简称NS-Ti2448合金)在37 ℃的模拟人体唾液(ASS)中的腐蚀行为，探索F-离子含量对该合金在模拟人体环境中电化学行为的影响。实验采用动电位极化曲线、电化学阻抗谱(EIS)、Mott-Schottky曲线等测试方法，对不同F-离子含量条件下NS-Ti2448合金的电化学性能展开研究。结果表明：在37 ℃的ASS溶液中，当F-离子含量较低(＜0.1%)时，NS-Ti2448合金表现出很好的耐蚀性；而当F-离子含量达到1%时，合金钝化膜的保护性迅速丧失，表现为Icorr增大，阻抗大幅度下降，合金在整个电位区间内为活性溶解，钝化膜内缺陷密度增大等特征。
关键字: Ti2448合金；电化学；模拟唾液；氟离子
（Shenyang National Laboratory for Materials Science, Institute of Metal Research,
Chinese Academy of Sciences, Shenyang 110016, China）
Abstract:The electrochemical behavior of the nanostructured Ti-24Nb-4Zr-8Sn (NS-Ti2448) alloy, for application as biomedical implant materials, was investigated in artificial saliva with various fluoride concentrations at 37 ℃. The aim of the present study was to evaluate the effect of F- on the corrosion performance of NS-Ti2448 alloy in the simulated body fluid, utilizing electrochemical impedance spectroscopy (EIS), Mott-Schottky test, as well as potentialdynamic polarization measurement. Very low current density (Jcorr) was obtained for the alloy when the fluoride was less than 0.1%, indicating a typical passive behavior and significantly low corrosion rate. With the fluoride concentration rising up to 1%, the electrochemical behavior changes to anodic dissolution, and the corrosion resistance dropped to a rather low level. EIS and Mott-Schottky results exhibited the same tendency, indicating a less stable and more defective film being formed with the fluoride concentration increasing.
Key words: Ti2448 alloy; electrochemistry; artificial saliva; F-
