Study of ductility mechanism of AuCuAl alloys with heusler structure and application to biofunctional materials

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K13655
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 18010:Mechanics of materials and materials-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Umise Akira 東京工業大学, 科学技術創成研究院, 助教 (60802353)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 形状記憶合金 / 超弾性 / 生体金属材料 / 微小試験 / 機械的性質 / 耐食性

Outline of Final Research Achievements

The purpose of this study is to clarify the ductility mechanism of AuCuAl alloys with heusler structure and its application to biofunctional materials. Intermetallic compounds with the heusler structure are expected to be applied to various functional materials such as ferromagnetic shape memory alloys and thermoelectric conversion materials, but they are very brittle in polycrystal. Therefore, we investigated the mechanism of grain boundary embrittlement in Au2CuAl-based alloys to verify the potential of this alloy for biomedical functional materials. The ductility of the material was improved by controlling the grain boundary shape by addition elements and by controlling the second phase. In addition, corrosion resistance was evaluated for use as a biofunctional material.

Free Research Field

生体金属材料

Academic Significance and Societal Importance of the Research Achievements

本研究対象であるAuCuAl基超弾性合金は①MRI アーチファクトフリー，②高レントゲン造影性があり，および，機能材料としては，③形状制御や応力保持のための超弾性・形状記憶効果があり，また生体材料として必要不可欠の④生体適合性（ニッケルなどの金属アレルギーのない元素で構成）を持つ現在において唯一無二の全てを兼ね備える生体機能材料の設計ができる可能性を有しているが，この合金おいても粒界脆化のため非常に脆いという問題がある．複雑な粒界形状が粒界脆化を抑制するという着想とその機構の解明は学問的に新しく独創的である．この機構を解明することで，機能材料としてホイスラー合金の革新的発展につながると考える．