氟離子含量對Ti2448納米晶在模擬唾液中腐蝕行為的影響Electrochemical behavior of nanostructured Ti2448 alloy in artificial saliva at 37 ℃ with fluoride

研究了經(jīng)冷軋納米化處理的醫(yī)用Ti-24Nb-4Zr-8Sn納米晶合金(簡稱NS-Ti2448合金)在37 ℃的模擬人體唾液(ASS)中的腐蝕行為，探索F^-離子含量對該合金在模擬人體環(huán)境中電化學(xué)行為的影響。實驗采用動電位極化曲線、電化學(xué)阻抗譜(EIS)、Mott-Schottky曲線等測試方法，對不同F(xiàn)^-離子含量條件下NS-Ti2448合金的電化學(xué)性能展開研究。結(jié)果表明：在37 ℃的ASS溶液中，當(dāng)F^-離子含量較低(＜0.1%)時，NS-Ti2448合金表現(xiàn)出很好的耐蝕性；而當(dāng)F^-離子含量達(dá)到1%時，合金鈍化膜的保護(hù)性迅速喪失，表現(xiàn)為I_corr增大，阻抗大幅度下降，合金在整個電位區(qū)間內(nèi)為活性溶解，鈍化膜內(nèi)缺陷密度增大等特征。

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 (J_corr) 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.

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