Departamento de Ingeniería Mecánica y Metalúrgica, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile.
Departamento de Ingeniería Mecánica y Metalúrgica, Escuela de Ingeniería, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile; Escuela de Construcción Civil, Facultad de Ingeniería, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile; Centro de Investigación en Nanotecnología y Materiales Avanzados "CIEN-UC", Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, Macul, Santiago, Chile.
Mater Sci Eng C Mater Biol Appl. 2020 Jun;111:110758. doi: 10.1016/j.msec.2020.110758. Epub 2020 Feb 19.
Porous titanium materials have gained interest as prosthesis materials due to their similar mechanical properties to the human bone, biocompatibility, and high corrosion resistance. The presence of pores in the metal matrix implies a decrease in the elastic modulus and an increase in the active area, perhaps improving the osseointegration. Corrosion resistance is a critical consideration as corrosion may lead not only to mechanical failure but also the release of ions and/or particles to the bloodstream. In this work, a novel Ti-Nb-Ta-Fe-Mn alloy with varying percentage of porosity (25, 31 and 37 v/v%) was exposed to simulated body fluid (SBF) at 37 °C and its corrosion resistance was investigated using electrochemical techniques and surface analysis as a function of exposure time. Open circuit potential and polarization curves revealed that the effect of porosity was mainly on the shift of the corrosion potential to more negative values with a slight increase in the anodic current. A passive range was also observed, which was not influenced either by increased exposure time or increased porosity. Therefore, a change in the surface specific area could have taken place during the exposure, which is not necessarily related to a corrosion process. Moreover, a typical porous electrode behavior was identified by electrochemical Impedance spectroscopy, without any significant change over time. No release of metal ions was detected by on line ICP-AES, either at the open circuit potential or upon polarizing the samples up to 2 V vs. SCE, whereas only traces elements (Fe and Mn 1 nmol/s cm) were detected in the electrolyte accumulating all released ions during 30 days of exposure. Additionally, the surface analysis showed thickening of the oxide layer with exposure time. Therefore, the stability of the passive layer and low release of ions indicate that the porous alloys are suitable for further study as prosthesis materials.
多孔钛材料因其与人体骨骼相似的机械性能、生物相容性和高耐腐蚀性而被用作假体材料。金属基体中的孔隙存在意味着弹性模量降低和有效面积增加，这可能改善了骨整合。耐腐蚀性是一个关键考虑因素，因为腐蚀不仅会导致机械失效，还会导致离子和/或颗粒释放到血液中。在这项工作中，一种新型的 Ti-Nb-Ta-Fe-Mn 合金具有不同的孔隙率（25、31 和 37 v/v%），在 37°C 的模拟体液（SBF）中进行了暴露，并通过电化学技术和表面分析研究了其耐腐蚀性，作为暴露时间的函数。开路电位和极化曲线表明，孔隙率的影响主要是通过将腐蚀电位更负移，同时略微增加阳极电流来实现的。还观察到一个钝化范围，该范围既不受暴露时间的增加影响，也不受孔隙率的增加影响。因此，在暴露过程中可能发生了表面比表面积的变化，这不一定与腐蚀过程有关。此外，通过电化学阻抗谱鉴定了典型的多孔电极行为，在整个时间过程中没有任何明显变化。在线 ICP-AES 也没有检测到金属离子的释放，无论是在开路电位还是在将样品极化至 2 V 对 SCE 时，而仅在电解质中检测到痕量元素（Fe 和 Mn 1 nmol/s cm），这些元素在 30 天的暴露过程中累积了所有释放的离子。此外，表面分析表明随着暴露时间的增加，氧化层变厚。因此，稳定的钝化层和低离子释放表明多孔合金适合进一步研究作为假体材料。
