Multi-scale microstructure analysis of Ti based alloys and development of practical materials

2018 Fiscal Year Final Research Report

• Project/Area Number: 26249104
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Structural/Functional materials
• Research Institution: University of Tsukuba
• Principal Investigator: Miyazaki Shuichi 筑波大学, 数理物質系, 特命教授 (50133038)
• Co-Investigator(Kenkyū-buntansha): 金 へよん 筑波大学, 数理物質系, 教授 (20333841)
• Project Period (FY): 2014-04-01 – 2019-03-31
• Keywords: マルテンサイト変態 / 形状記憶合金 / 超弾性合金 / チタン合金 / 集合組織 / 力学特性 / 生体材料

Outline of Final Research Achievements

In order to develop novel Ti-based superelastic alloys with large superelastic recovery strain and high strength, Ti-Zr based multi-component alloys were designed, and the transformation characteristics and deformation behavior were investigated. The effects of alloying elements on the crystal structure, phase stability, martensitic transformation behavior and superelastic properties were investigated quantitatively. The compositional dependence of martensitic transformation temperature and transformation strain was clarified, and a composition range exhibiting large superelastic recovery strain was established. It has been found that low Young's modulus and high strength can be simultaneously achieved through the control of phase stability and optimization of recrystallization texture.

Free Research Field

構造・機能材料

Academic Significance and Societal Importance of the Research Achievements

生体用機能材料として注目を浴びているチタン合金を対象として、マルテンサイト変態温度、結晶構造、格子変形歪みの組成依存性を明らかにし、優れた特性を有する生体用形状記憶・超弾性合金の合金設計指針を見出した。実用レベルの新合金開発だけではなく、チタン合金のマルテンサイト変態や変形メカニズムの解明に繋がる優れた結果が得られた。また特性を最大限引き出す加工熱処理法・組織制御法を明らかにした。また、低ヤング率・高強度合金開発の新たな可能性を切り開く有用な成果が得られ、医療分野への応用が進展することが期待される。