In-situ monitoring of the electrochemical behavior of cellular structured biomedical Ti-6Al-4V alloy fabricated by electron beam melting in simulated physiological fluid
In-situ monitoring of the electrochemical behavior of cellular structured biomedical Ti-6Al-4V alloy fabricated by electron beam melting in simulated physiological fluid
复制标题
模拟生理液中电子束熔炼制备的细胞结构生物医用 Ti-6Al-4V 合金电化学行为的原位监测
DOI：
10.1016/j.actbio.2020.02.008
复制
发表时间：
2020-04-01
影响因子：
9.7
通讯作者：
Misra, R. D. K.
中科院分区：
文献类型：
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作者：
Gai, Xin;Bai, Yun;Misra, R. D. K.
添加法制备的具有胞状结构的Ti-6Al-4V合金具有与骨相当的弹性系数，并且胞状结构允许细胞穿透和交换营养物质，从而促进了骨整合，因此受到了广泛的关注。我们描述了一种独特的模拟装置，它取代了传统的稳态电化学方法，能够原位研究在磷酸盐缓冲盐水(PBS)中电子束熔炼(EBM)制备的胞状结构Ti-6Al-4V合金的离子浓度和表面电位随孔深的变化。这种方法解决了细胞结构钛合金的电化学行为方面的科学空白。研究表明，H+和Cl-的浓度随孔深的增加而增加，而表面电位则降低。在37℃的PBS中浸泡14天后，内部细胞结构的裸露表面没有被腐蚀，而是钝化了，这与孔深无关。此外，X射线光电子能谱(XPS)和莫特-肖特基(M-S)研究表明，在胞状结构的Ti-6Al-4V合金表面形成了一层较薄的钝化膜，在最深的孔深处含有较高的施主密度。这归因于氧供应不足和孔内表面的氯吸附。意义陈述多孔钛合金在生物医学应用中是很有前途的植入物。然而，用传统的电化学方法准确表征具有复杂孔结构的多孔钛合金的腐蚀行为是一个挑战。在本研究中，我们采用了一种特殊的装置来模拟孔隙结构内的环境。对EBM制备的Ti-6Al-4V的离子浓度和表面电势随孔深的变化进行了实时监测。在PBS中浸泡14d后，Ti-6Al-4V表现出良好的腐蚀性能，孔深小于60 mm的样品未被腐蚀，而是钝化。并分析了不同孔隙深度下腐蚀性能的差异。这种类型的现场腐蚀性能监测在EBM生产的Ti-6Al-4V中以前还没有研究过。(C)2020 Acta Materialia Inc.由爱思唯尔有限公司出版。版权所有。
Ti-6Al-4V alloys with cellular structure fabricated by additive manufacturing are currently of significant interest because their modulus is comparable to bone and the cellular structure allows the cells to penetrate and exchange nutrients, promoting osseointegration. We describe here a unique simulation device that replaces the traditional steady electrochemistry approach, enabling in-situ study of variation of ion concentration and surface potential with pore depth for cellular structured Ti-6Al-4V alloys fabricated by electron beam melting (EBM) in phosphate buffered saline (PBS). This approach addresses the scientific gap on the electrochemical behavior of cellular structured titanium alloys. The study indicated that concentration of H+ and Cl- increased with the increase of pore depth, while the surface potential decreased. The exposed surface of inner cellular structure was not corroded but passivated after immersing in PBS at 37 degrees C for 14 days, which was independent of pore depth. Furthermore, X-ray photoelectron spectroscopy (XPS) and Mott-Schottky (M-S) studies suggested that a thinner passive film containing a greater donor density was formed on the surface of cellular structured Ti-6Al-4V alloy at the deepest pore depth. This is attributed to insufficient oxygen supply and Cl adsorption on the surface inside the pores.Statement of SignificancePorous titanium alloys are promising implants in biomedical applications. However, it is a challenge to accurately characterize the corrosion behavior of porous titanium alloys with complex pore structure using traditional electrochemical methods. In this study, we have adopted a special device to simulate the environment within the pore structure. The variation in ion concentration and surface potential of Ti-6Al-4V fabricated by EBM with pore depth was in-situ monitored. After immersing in PBS for 14 days, Ti-6Al-4V exhibited good corrosion properties and the samples with less than 60 mm pore depth were not corroded but passivated. Also, we analyzed the difference in corrosion property at different pore depth. This type of in-situ corrosion performance monitoring in EBM-produced Ti-6Al-4V has not been previously studied. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.