2023 Fiscal Year Final Research Report
Development of a computation system for grain boundary and dislocation segregation in structural materials and microstructure control by segregation design
| Project/Area Number |
21H01676
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Review Section |
Basic Section 26050:Material processing and microstructure control-related
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| Research Institution | National Institute for Materials Science |
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Principal Investigator |
OHNUMA Ikuo 国立研究開発法人物質・材料研究機構, 構造材料研究センター, 主席研究員 (20250714)
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| Project Period (FY) |
2021-04-01 – 2024-03-31
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| Keywords | 結晶粒界偏析 / CALPHAD法 / 熱力学・拡散データベース / 鉄鋼材料 / 銅合金 / アルミニウム合金 / 格子欠陥 / 核生成 |
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| Outline of Final Research Achievements |
It is well known that grain boundary segregation of solute and impurity elements has significant effects on the microstructure and properties of various structural materials, including iron and steel materials. In this study, the grain boundary phase model based on the parallel tangent law proposed by Hillert is extended to cover various types of segregated elements in structural materials such as steel, Cu alloys and Al alloys, taking into account (1) the interaction effect between segregated elements on complex segregation, (2) grain size, (3) grain boundary energy and (4) temperature dependence of grain boundary segregation. The accuracy of the calculation system was verified by comparison with experimental results. In addition, phase diagrams were determined experimentally and thermodynamic analyses were carried out to improve the accuracy of the thermodynamic database of the alloys to be calculated.
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| Free Research Field |
材料組織学
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| Academic Significance and Societal Importance of the Research Achievements |
粒界偏析が材料の諸特性に及ぼす影響が広く知られているが，複数元素を溶質とする多元系多結晶合金における粒界偏析を定量的に予測する手法の確立には至っていなかった．本研究により構築された『結晶粒界偏析計算システム』により，多元系合金における粒界偏析濃度を定量的に予測することが可能となり，粒界偏析効果を制御する手法が確立された社会的意義は非常に大きい．さらに，結晶粒界への偏析，さらには転位や積層欠陥など他の格子欠陥への溶質元素の偏析計算に展開できれば，析出物の核生成の前駆段階となるクラスター形成の予測と制御にも計算システムが拡張できると考えられ，学術的な展開が期待できる．
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