Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.
Institute of Innovative Research (IIR), Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan.
J Mech Behav Biomed Mater. 2022 Sep;133:105358. doi: 10.1016/j.jmbbm.2022.105358. Epub 2022 Jul 7.
In view of the urgent demands of shape memory alloys (SMAs) for biomedical applications due to the world population aging issue, the mechanical properties and functionalities of the biocompatible Ti-Au-Cr-based SMAs, which are tailored by Ta additions, have been developed in this study. The quaternary SMAs were successfully manufactured by physical metallurgy techniques and their mechanical properties and functionalities were examined. In the continuous tensile tests, it was found that the correlation between the yielding strength and phase stability followed a typical trend of mechanical behavior of SMAs, showing the lowest yielding strength at the metastable β-parent phase. Functional mappings between the alloy strength and elongation revealed that compared to the Ta-free specimen, the ductility was promoted 50% while the strength remained intact through the 4 at.% introduction of Ta. Slight shape recovery was observed in the cyclic loading-unloading tensile tests during the unloading process and the highest shape recovery was found in the Ti-4 at.% Au-5 at.% Cr-4 at.% Ta specimen. This indicates that the 4 at.% Ta tailored Ti-Au-Cr SMAs could be a promising material for biomedical applications.
鉴于世界人口老龄化问题对形状记忆合金（SMA）在生物医学应用方面的迫切需求，本研究通过添加 Ta 来开发具有生物相容性的 Ti-Au-Cr 基 SMA 的机械性能和功能。通过物理冶金技术成功制造了四元 SMA，并对其机械性能和功能进行了研究。在连续拉伸试验中，发现屈服强度与相稳定性之间的相关性遵循 SMA 机械行为的典型趋势，即在亚稳β-母相处表现出最低的屈服强度。合金强度与伸长率之间的功能映射表明，与不含 Ta 的样品相比，通过引入 4 at.% Ta，延展性提高了 50%，而强度保持不变。在卸载过程中的循环加载-卸载拉伸试验中观察到轻微的形状恢复，在 Ti-4 at.% Au-5 at.% Cr-4 at.% Ta 样品中发现了最高的形状恢复。这表明 4 at.% Ta 定制的 Ti-Au-Cr SMA 可能是一种有前途的生物医学应用材料。
