2021 Fiscal Year Final Research Report
Deformation mechanisms of hard mateials by non-conventional dislocation motion involving cooperative atomic shuffling
Project/Area Number |
20K21084
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Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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Allocation Type | Multi-year Fund |
Review Section |
Medium-sized Section 26:Materials engineering and related fields
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Research Institution | Kyoto University |
Principal Investigator |
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Project Period (FY) |
2020-07-30 – 2022-03-31
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Keywords | 変形機構 / 転位 / 硬質材料 / 協調原子運動 |
Outline of Final Research Achievements |
Room temperature deformation behavior of hard crystals with complex crystal structure, including Fe-Cr sigma phase and transition metal silicides, has been investigated by micropillar compression method. Operative deformation modes and their critical resolved shear stress for most materials investigated have been identified successfully. In Fe-Cr sigma phase, the activation of non-conventional slip by the motion of so-called zonal dislocations has been experimentally confirmed for the first time through the direct observation of the dislocation core structure by the atomic resolution electron microscopy. Atomic shuffling model in the dislocation core region has been proposed based on the observation. Knowledge gained on the dislocation core structure will lead to improved understanding of deformation mechanisms in this and other complex crystal structures and provide ways to improve the brittleness of these complex materials.
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Free Research Field |
金属物性
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Academic Significance and Societal Importance of the Research Achievements |
本研究で得たFe-Cr系σ相における特異な転位の転位芯構造に関する知見はこの材料だけでなく,これまで実験的証拠の欠如のため十分に検討されてこなかった他の複雑構造を有する結晶性材料の変形機構の理解を深化させることにつながるため,学術的に非常に重要で意義がある.また本研究で得た他の硬質材料の室温塑性変形に関する結果とともに,各種硬質結晶材料の各種構造材料の強化相としての実用化の際の問題の一つである室温脆性の改善策の提案にもつながる重要な知見であるため,工業的・社会的にも十分に意義がある.
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