Acceleration of Molecular Dynamics for Atomistic Understanding of Microstructure Formation Dynamics

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02415
• 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: The University of Tokyo
• Principal Investigator: Shibuta Yasushi 東京大学, 大学院工学系研究科(工学部), 准教授 (90401124)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 金属物性 / 時間加速分子動力学 / メタダイナミクス / 非平衡界面物性 / 自由エネルギー曲面探索 / スローダイナミクス

Outline of Final Research Achievements

In this study, a new virtual atom acceleration method is developed by extending Collected Variable driven Hyperdynamics (CVHD) method, which is one of the acceleration methods for molecular dynamics (MD) simulations. This method enables time acceleration of solute diffusion not only in an institutional solid solution (Fe-C) but also in a substitutional solid solution (Fe-Cr). Furthermore, we have developed a new method for calculating the solid-liquid interfacial energy at non-equilibrium interfaces (outside the melting point) without defining the liquid phase by applying the free energy surface search method based on metadynamics. Using this method, we investigated the temperature dependence of the interfacial energy of pure iron solid-liquid interfaces and found that the interfacial energy increases with increasing undercooling temperature.

Free Research Field

マテリアルモデリング

Academic Significance and Societal Importance of the Research Achievements

本研究において新たに開発した，数値シミュレーションに基づく非平衡温度下における界面物性温度依存性導出手法は，実験的に計測が困難な高温物性値の理解を可能にし，材料組織予測技術の高精度化に貢献できる．また数値シミュレーションに基づく材料組織学の新たな学理発展が期待される．