Refining the Theory of Stress-Induced Martensitic Transformation by Multi-Objective In-Situ Analysis

2022 Fiscal Year Final Research Report

• Project/Area Number: 19H02417
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26010:Metallic material properties-related
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Tahara Masaki 東京工業大学, 科学技術創成研究院, 准教授 (80610146)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: マルテンサイト変態 / 形状記憶合金 / 超弾性 / 応力誘起変態 / 単結晶

Outline of Final Research Achievements

The crystallographic features of stress-induced martensitic transformation were observed and measured in situ using state-of-the-art analytical equipment to reexamine conventional crystallographic theories. Stress-induced martensite was conventionally considered to be the same as thermally martensite. Detailed analysis in this study reveals that stress-induced martensite is generated by changing the lattice parameter while maintaining the compatibility of the interface with the parent phase.

Free Research Field

金属組織学

Academic Significance and Societal Importance of the Research Achievements

応力誘起マルテンサイト変態は形状記憶合金が持つ「超弾性」機能の根幹をなす現象であるにもかかわらず、1980年代に行われた研究以降、基礎的研究が十分に行われてこなかった。本研究の成果は応力誘起変態の学術的基礎の再検証に資すると考える。また、得られた成果は超弾性機能の向上に向けた材料設計理論の構築に今後重要な役割を果たすものである。