Evaluation of size effect and critical size for perfect shape recovery in shape memory alloy by micro-sized testing

2016 Fiscal Year Final Research Report

• Project/Area Number: 15K14159
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Structural/Functional materials
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Inamura Tomonari 東京工業大学, 科学技術創成研究院, 准教授 (60361771)
• Co-Investigator(Renkei-kenkyūsha): HOSODA Hideki 東京工業大学, 科学技術創成研究院, 教授 (10251620) ; TAHARA Masaki 東京工業大学, 科学技術創成研究院, 助教 (80610146) ; SONE Masato 東京工業大学, 科学技術創成研究院, 教授 (30323752)
• Project Period (FY): 2015-04-01 – 2017-03-31
• Keywords: 生体用形状記憶合金 / 微小材料試験 / サイズ効果

Outline of Final Research Achievements

Evaluation of size-effect of shape memory properties is necessary because the size of the material is becoming smaller in medical devices such as stents which is made of shape memory alloys. Effects of specimen size on shape memory properties is investigated in Au-based and Ti-based shape memory alloys using micro-testing machine in this study. The stress-induced martensite transformation behavior is independent of the specimen size (in the order of 10 micron meter), whereas superelastic deformation behavior seemed to be affected by the relative size between martensite plates and specimen size. Micro-sized specimen exhibited ductile plastic deformation behavior and perfect superelasticity even though the macro-sized specimen is brittle.

Free Research Field

金属組織学