Comibinatorial evaluation of Ti-Ni based high formable shape memory alloys

2019 Fiscal Year Final Research Report

• Project/Area Number: 17H03143
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Materials/Mechanics of materials
• Research Institution: Nagoya University
• Principal Investigator: Junpei Sakurai 名古屋大学, 工学研究科, 准教授 (40345385)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 形状記憶合金 / 金属ガラス / コンビナトリアル / MEMS

Outline of Final Research Achievements

A combinatorial method was used to search and evaluate the physical properties of highly formable shape memory alloys. These alloys become metallic glass when they are amorphous state, and after crystallization they show shape memory effect. In this research, we succeeded in searching for new Ti-Ni-Hf high formable shape memory alloys. In addition, library fabrication methods and combinatorial evaluation for thermal properties and biocompatibility by using anodic polarization test were established evaluation of these alloys. We evaluated the biocompatibility of Ti-Ni-Zr and Ti-Ni-Cu highly formable shape memory alloys and clarified that the components of the passivation film differ depending on the alloy system. It was clarified that the Ti-Ni-Cu has excellent biocompatibility.
Finally, a foldable pipe structure was produced using this alloy, and it showed excellent formability and shape memory characteristics.

Free Research Field

金属工学，機械工学，MEMS

Academic Significance and Societal Importance of the Research Achievements

今回評価したTi-Ni系高成形性形状記憶合金は，非晶質時金属ガラスの特性を示すにも関わらず，結晶化後脆化することなく良好な形状記憶特性を示すことが明らかになった．材料の主たる機能としては結晶質の形状記憶特性や超弾性になるが，製作時の非晶質時の特性に注目することで，本合金の欠点であった加工性を克服することができた．形状記憶合金は医療用など様々な分野に応用されているが，加工性の欠点を克服することで，多様なデバイスへの応用が可能となる．
また，コンビナトリアル手法を用いることで効率的に材料探索や物性評価を行うことが可能となり，材料開発を加速することができた．