Observation of local deformation behavior of microstructure formed through displacive transformation

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02475
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 26050:Material processing and microstructure control-related
• Research Institution: The University of Tokyo
• Principal Investigator: Inoue Junya 東京大学, 生産技術研究所, 教授 (70312973)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: デジタルホログラフィック顕微鏡 / 変位型変態 / 組織形成 / 局所変形挙動 / Wavelet変換

Outline of Final Research Achievements

The analysis of heterogeneous deformation behavior at the grain level has been attracting attention, and considered as an important technology for achieving higher performance in metallic materials. Therefore, analysis using AFM, SEM/EBSD, TEM, etc. are widely used to elucidate local deformation behavior. There is, however, a limit to both real-time performance and measurement accuracy. Accordingly, in this study, we aimed to construct a new method to measure nano-scale changes in surface undulations caused by transformation strain and plastic deformation in real time.
As a result, we developed a 3D shape reconstruction method using the Wavelet transform, and enabled the reproduction of fine surface undulations.

Free Research Field

データ駆動型材料科学

Academic Significance and Societal Importance of the Research Achievements

鉄鋼材料の高機能化や高強度化の鍵として，近年マルテンサイト変態等の変位型相変態が盛んに研究されている。この様な組織形成を理解し，構造材料の長期的な信頼性を向上する上では，形成相やその周辺で生じる変形挙動の解明が極めて重要である。特に，高強度化と高延性化の両立を目指しす上では，形成相の形態や体積率の制御が重要であり，その最適化には異相界面や高強度相で生じるひずみの局所化挙動の理解が不可欠となっている。本研究は，この様な変位型変態組織の形成過程や変形挙動を支配するメカニズムを解明する上で不可欠となる，新たな計測手法を提供するものである。