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采用开路电位、动电位极化曲线和电化学阻抗谱(EIS)测量方法研究了新型医用钛合金Ti-35Nb-4Sn-6Mo-9Zr和Ti-35Nb-1.3Mo-3.7Zr在林格溶液中的电化学腐蚀行为,计算了2种合金在林格溶液中的腐蚀电位(φcorr)、腐蚀电流(Icorr)及钝化电流(Ipass),并根据EIS曲线建立了等效电路进行参数分析,同时与Ti-6A1-4V(TC4)合金进行比较。结果表明:Ti-35Nb-4Sn-6Mo-9Zr、Ti-35Nb-1.3Mo-3.7Zr和TC4合金的Icorr和Ipass依次增大,而φcorr依次减小。EIS结果分析显示,3种合金在林格溶液中均可形成致密内层和疏松外层的双层钝化膜,其中致密内层钝化膜对合金表面的保护起主要作用。3种合金的致密内层的阻挡作用按TC4、Ti-35Nb-1.3Mo-3.7Zr和Ti-35Nb-4Sn-6Mo-9Zr的顺序递增。
The effects of Ti-35Nb-4Sn-6Mo-9Zr and Ti-35Nb-1.3Mo-3.7Zr on Ringer’s solution were studied by open circuit potentiometry, potentiodynamic polarization curve and electrochemical impedance spectroscopy (EIS) The corrosion potential (φcorr), corrosion current (Icorr) and passivation current (Ipass) of the two alloys in Ringer’s solution were calculated. The equivalent circuit was established according to the EIS curve for parameter analysis. At the same time, Ti-6A1-4V (TC4) alloy for comparison. The results show that the Icorr and Ipass of Ti-35Nb-4Sn-6Mo-9Zr, Ti-35Nb-1.3Mo-3.7Zr and TC4 alloy increase in turn, while φcorr decreases in turn. The results of EIS show that the three kinds of alloys can form a double passivation film with dense inner layer and loose outer layer in the Ringer solution. The dense inner passivation film plays a key role in the protection of the alloy surface. The barrier effect of the dense inner layer of the three alloys was increased in order of TC4, Ti-35Nb-1.3Mo-3.7Zr and Ti-35Nb-4Sn-6Mo-9Zr.