The corrosion behaviour of Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr in protein solutions
The corrosion behaviour of Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr in protein solutions
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DOI：
10.1016/s0142-9612(98)00217-8
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发表时间：
1999-04-01
期刊：
影响因子：
14
通讯作者：
Williams, DF
中科院分区：
文献类型：
--
作者：
Khan, MA;Williams, RL;Williams, DF
钛合金由于其适当的机械性能和优异的耐腐蚀性而用于骨科应用。据报道，由于被动腐蚀或加速过程（如磨损），钛和其他合金元素释放到周围组织中。由于钝化层在某些情况下可以通过磨损而分解，因此研究这些合金在生物环境中（特别是在蛋白质存在下）再钝化的能力并评估再钝化表面与原始表面的差异是很重要的。在本研究中，我们研究了Ti-6Al-4V、Ti-6Al-7 Nb和Ti-13 Nb-13 Zr在不同pH值和不同白蛋白浓度下在磷酸盐缓冲盐水（PBS）、PBS中的牛白蛋白溶液和PBS中的10%胎牛血清中再钝化的能力。结果发现，pH值的增加对Ti-6Al-4V和Ti-6Al-7 Nb在PBS中的腐蚀行为的影响大于对Ti-13 Nb-13 Zr的影响，并且向PBS中添加蛋白质降低了pH值对所有合金的腐蚀行为的影响。通过测量合金表面硬度的变化来研究腐蚀和再钝化的效果，并且发现腐蚀降低了所有合金的表面氧化物的硬度。在PBS中，Ti-6Al-4V的降低最小，Ti-13 Nb-13 Zr的降低最大，并且蛋白质溶液中的腐蚀进一步降低了表面氧化物的硬度。Ti-6Al-4V和Ti-6Al-7 Nb的这种影响大于Ti-13 Nb-13 Zr。总之，环境中的蛋白质似乎与这些合金表面的再钝化过程相互作用，并影响所得的表面性质。(C)1999 Elsevier Science Ltd.保留所有权利。
Ti alloys are used in orthopaedic applications owing to their appropriate mechanical properties and their excellent corrosion resistance. The release of titanium and the other alloying elements into the surrounding tissue has been reported due either to passive corrosion or accelerating processes such as wear. Since the passive layer can be broken down in certain circumstances by wear it is important to study the ability of these alloys to repassivate in biological environments, in particular in the presence of proteins, and evaluate how the repassivated surface may vary from the original surface. In this study we investigated the ability of Ti-6Al-4V, Ti-6Al-7Nb and Ti-13Nb-13Zr to repassivate in phosphate buffered saline (PBS), bovine albumin solutions in PBS and 10% foetal calf serum in PBS at different pH values and at different albumin concentrations. It was found that an increase in pH had a greater effect on the corrosion behaviour of Ti-6Al-4V and Ti-6Al-7Nb than on Ti-13Nb-13Zr in PBS and that the addition of protein to the PBS reduced the influence of pH on the corrosion behaviour of all the alloys. The effect of the corrosion and repassivation was investigated by measuring changes in the surface hardness of the alloys and it was found that corrosion reduced the hardness of the surface oxides of all the alloys. In PBS the reduction was smallest for Ti-6Al-4V and largest for Ti-13Nb-13Zr and that corrosion in protein solutions further reduced the hardness of the surface oxides. This effect was greater for Ti-6Al-4V and Ti-6Al-7Nb than for Ti-13Nb-13Zr. In conclusion, proteins in the environment appear to interact with the repassivation process at the surface of these alloys and influence the resulting surface properties. (C) 1999 Elsevier Science Ltd. All rights reserved.