| Project/Area Number |
21K20418
|
|---|
| Research Category |
Grant-in-Aid for Research Activity Start-up
|
| Allocation Type | Multi-year Fund |
|---|
| Review Section |
0301:Mechanics of materials, production engineering, design engineering, fluid engineering, thermal engineering, mechanical dynamics, robotics, aerospace engineering, marine and maritime engineering, and related fields
|
|---|
| Research Institution | Japan Atomic Energy Agency |
|---|
Principal Investigator |
Lobzenko Ivan 国立研究開発法人日本原子力研究開発機構, 原子力科学研究部門 原子力科学研究所 原子力基礎工学研究センター, 博士研究員 (30802293)
|
|---|
| Project Period (FY) |
2021-08-30 – 2023-03-31
|
| Project Status |
Completed (Fiscal Year 2022)
|
| Budget Amount *help |
¥3,120,000 (Direct Cost: ¥2,400,000、Indirect Cost: ¥720,000)
Fiscal Year 2022: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2021: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
|
|---|
| Keywords | Metallic glass / Atomic stress / First-principles / LCAO / Shear softening / Shear deformation |
|---|
| Outline of Research at the Start |
Metallic glass has a great potential for the advanced structural materials achieving high strength and high ductility. However, the deformation mechanism of metallic glass has not been fully understood yet. The aim of this study is to explore correlations in the atomic level properties and revealing origins of deformation in metallic glass based on the new methodology of "atomic level stress".
|
| Outline of Final Research Achievements |
The behavior of metallic glass under strain is not fully understood yet due to its essentially emergent nature, and the gap between macroscopic mechanical properties and the microscopic responses remains open. In this study, we employ a unique technique of atomic stress calculations in the first principles framework to build a comprehensive picture of metallic glass response to the shear strain using the CuZr amorphous system as an example. The Cu and Zr subsystems of the glass were found to be different in developing the response by examination of the local parameters, among which are von Mises stress, charge transfer, and change of electronic partial density of states at the Fermi level. We show the significance of atomic von Mises stress by showing its stronger correlation with D2min (deviation from the linear strain on each atom). Overall the behavior of CuZr metallic glass under shear strain is thoroughly described in this study from mechanical and electronic points of view.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究は、一般的な古典的分子動力学（MD）シミュレーションよりも信頼性の高い密度汎関数理論（DFT）の手法を用いた高精度な第一原理計算によって実施されたものである。このような枠組みでは使われることのなかった原子応力計算に基づくvon Mise応力を計算し、このパラメータが古典的MDで得られた結果と比較できることを示す。一般的に用いられるせん断応力とは対照的に、von Mises応力はすべての応力成分の変化を捉えることができるため、不均質性の高い系に対してより信頼性が高い。CuZrの力学的挙動の理解により、材料の劣化について予見することが可能となることから、意義を有している。
|
