XPS and EIS study of the passive film formed on orthopaedic Ti-6Al-7Nb alloy in Hank's physiological solution
XPS and EIS study of the passive film formed on orthopaedic Ti-6Al-7Nb alloy in Hank's physiological solution
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DOI：
10.1016/j.electacta.2007.12.041
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发表时间：
2008-03-20
影响因子：
6.6
通讯作者：
Strehblow, H. -H.
中科院分区：
文献类型：
--
作者：
Milosev, I.;Kosec, T.;Strehblow, H. -H.
用X射线光电子能谱（XPS）和电化学阻抗谱（EIS）研究了Ti-6Al-7 Nb合金在Hank’s生理溶液中电化学氧化形成的钝化膜的组成和结构。氧化物层主要是TiO 2，但含有少量的低价氧化物TiO和TiO 2 O 3在更负的电位比0.75 V。在更正的电位，TiO是唯一的形式。在较低的电位范围内形成的低氧化物是不太明显的比在Ti-6Al-4V合金。在汉克的生理溶液中的被动范围是广泛的，并将LIP扩展到6.0 V。氧化铝Al 2 O3和铌氧化物Nb 2 O 5和NbO和/或NbO 2被纳入被动层。角分辨XPS分析证实，它们主要位于外部氧化物/溶液界面的TiO 2基质。氧化物层的厚度取决于氧化电位，并且在5.75 V下氧化后，其达到9.4 nm。EIS测量与XPS数据相关良好。合金元素的氧化物结合到TiO 2层中反映在高阳极电位和较长浸渍时间下外层电阻的增加。该过程的结果有利于Ti-6Al-7 Nb合金在生理条件下的整体稳定性和高耐腐蚀性。(c)2007爱思唯尔有限公司版权所有。
The composition and Structure of the passive film formed on Ti-6Al-7Nb alloy by electrochemical oxidation in Hank's physiological solution Were Studied using X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS). The oxide layer was predominantly TiO2, but contained small amounts of suboxides TiO and Ti2O3 at potentials more negative than 0.75 V. At more positive potentials, TiO, was the only form. The formation of suboxides in the lower potential range is less pronounced than in Ti-6Al-4V alloy. The passive range in Hank's physiological solution is broad and extends LIP to 6.0 V. Aluminium oxide Al2O3, and niobium oxides, Nb2O5, and NbO and/or NbO2, are incorporated in the passive layer. Angular resolved XPS analysis confirmed that they are located mainly at the outer oxide/solution interface of the TiO2 matrix. The thickness of the oxide layer was dependent on the oxidation potential and, after oxidation at 5.75 V, it reached 9.4 nm. EIS measurements correlate well with the XPS data. The incorporation of the oxides of alloying elements into the TiO, layer is reflected in the increase in the outer layer resistance at high anodic potentials and longer immersion times. The consequences of this process are beneficial for the overall stability and high corrosion resistance of the Ti-6Al-7Nb alloy under physiological conditions. (c) 2007 Elsevier Ltd. All rights reserved.