2020 Fiscal Year Final Research Report
Sciences in nano-meter incision: observation and modeling by atomic simulation
| Project/Area Number |
18K18939
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 26:Materials engineering and related fields
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| Research Institution | Gifu University |
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Principal Investigator |
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| Project Period (FY) |
2018-06-29 – 2021-03-31
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| Keywords | ナノメトリック切断 / インデンテーション / 応力集中 / 塑性変形 / 分子動力学シミュレーション |
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| Outline of Final Research Achievements |
Focusing on the “indentation-cutting” that bisects target materials not by shear force but by penetration of sharp blade, various molecular dynamics simulations are performed on the indentation and cutting of crystalline metals by 2D-like infinite rigid blade. As a definite difference between 3D nano indentation and 2D-like infinite blade, plastic deformation easily occurs from 2D blade without large elastic deformation under indenter, so that there is no “Pop-in” response that actively discussed in 3D indentation. Another important mechanism is also found; that is, a “skin” is formed on the blade surface, of which crystal orientation is coincident with that of the blade surface. It is revealed that subgrain formation, rotation and slips between the skin and base metal play important roles in change in the roughness of the cutting surface or cutting direction.
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| Free Research Field |
計算固体力学，分子動力学
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| Academic Significance and Societal Importance of the Research Achievements |
３Dナノインデンテーションとの違いから明白になったこととして，刃を極限まで鋭利にすることは，塑性変形を発生させるための応力集中を極限まで高めることに他ならない，ということである．したがって，刃先に生じる応力集中→塑性変形をナノレベルでコントロールすることで新しい切断の方法論につながると思われる．一方，プラスチックなど高分子材料については「塑性変形」の定義が金属に比べて曖昧であり，切断されたプラスチックは局所的にC-Cの共有結合が切れているのか，分子鎖がすり抜けて流動変形しているだけなのか，今後さらなる研究が期待される．
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