Hwang Yu-Jin, Lee Dong-Geun
Materials Metallurgical Engineering, Sunchon National University, Suncheon 57922, Republic of Korea.
J Nanosci Nanotechnol. 2019 Jul 1;19(7):3811-3815. doi: 10.1166/jnn.2019.16272.
For metals to be used as biomaterials, there must not be harmful reaction between the corrosion product of metal or eluted ion, and bio-tissue. Titanium is one of the excellent bio-compatible materials and generally it has tendency to have a small amount elution of Ti ions inside the body. Titanium alloy need to have low elastic modulus for reducing the stress shield effect. Ti-39Nb-6Zr alloy which is consist of biocompatible element such as Nb and Zr, has low elastic modulus with below 60 GPa, but it shows lower yield stress and tensile stress compared with Ti-6Al-4V alloy. In order to increase the strength of Ti-39Nb-6Zr alloy, aluminum was added in this alloy. Since aluminum elements are reported to lead to Alzheimer disease in human, high corrosion resistance is required to use Ti-39Nb-6Zr-0.45Al alloy containing a small amount of Al. In this study, corrosion behaviors were investigated under the solution of three conditions of 0.9% NaCl (pH 7), 0.1% NaF (pH 3) and 0.1% NaF (pH 5). The behaviors were stable under all the conditions. But Ti-39Nb- 6Zr-0.45Al alloy had better corrosion resistance than Ti-39Nb-6Zr alloy in all the conditions. This is because oxide mixtures such as Al₃TiO₂, Al₂TiO are formed inside the surface layer, which results in forming more stable oxide film than TiO₂ surface film. Ti-39Nb-6Zr-0.45Al alloy has high corrosion resistance and can reduce the concern about aluminum ion elution inside the body.
要将金属用作生物材料，金属的腐蚀产物或溶出离子与生物组织之间不得发生有害反应。钛是一种优良的生物相容性材料，一般来说，其在体内的钛离子溶出量较少。钛合金需要具有低弹性模量以降低应力屏蔽效应。由铌和锆等生物相容性元素组成的Ti-39Nb-6Zr合金，其弹性模量低于60 GPa，具有低弹性模量，但与Ti-6Al-4V合金相比，其屈服应力和拉伸应力较低。为了提高Ti-39Nb-6Zr合金的强度，在该合金中添加了铝。由于据报道铝元素会导致人类患阿尔茨海默病，因此使用含有少量铝的Ti-39Nb-6Zr-0.45Al合金需要具有高耐腐蚀性。在本研究中，研究了在0.9% NaCl（pH 7）、0.1% NaF（pH 3）和0.1% NaF（pH 5）三种条件的溶液中的腐蚀行为。在所有条件下，这些行为都是稳定的。但在所有条件下，Ti-39Nb-6Zr-0.45Al合金的耐腐蚀性均优于Ti-39Nb-6Zr合金。这是因为在表面层内部形成了Al₃TiO₂、Al₂TiO等氧化物混合物，这导致形成比TiO₂表面膜更稳定的氧化膜。Ti-39Nb-6Zr-0.45Al合金具有高耐腐蚀性，并且可以减少对体内铝离子溶出的担忧。
