Non-equiblirium growth behavior of interface migrated with solute segregation

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H02473
• 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: Tohoku University
• Principal Investigator: Miyamoto Goro 東北大学, 金属材料研究所, 准教授 (60451621)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 相変態 / エネルギー散逸 / ソリュートドラッグ / 偏析 / 三次元アトムプローブ / 界面整合性

Outline of Final Research Achievements

In order to control the phase transformation microstructure that develops during heat treatment of steels, the effects of Mo, Mn, and Ni additions on the interfacial migration of interphase boundary were investigated. Mo segregates at the interface and consumes a large amount of energy for interfacial migration, but the effect disappears when the migration velocity is small. On the other hand, Mn consumes a large amount of energy regardless of the interfacial migration velocity and suppresses interfacial migration even at slow interfacial migration velocities. Furthermore, 3DAP analyses reveal the nanoscale elemental enrichment near the interface that causes these energy consumption and it was found that the enrichment behavior differs greatly depending on the interfacial character. A model was developed to quantitatively predict these elements behavior, and a parameterization method was proposed for each interface parameter.

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Free Research Field

金属材料組織学

Academic Significance and Societal Importance of the Research Achievements

本研究で明らかになった添加元素と異相界面の相互作用の定量的な理解は、鉄鋼材料を始めとする構造用金属材料の高機能化に資するものであると同時に、少ない添加元素で効率的に相変態挙動を制御することができるようになるため、省資源化にも貢献することが期待される。また、異相界面における添加元素の振る舞いが明確になったことから、これまで想像するしかなかった界面における精緻な元素活用を可能にするものである。