2022 Fiscal Year Final Research Report
Mechanism of Embryo Formation of Fatigue Fracture at Heterophase Interfaces
| Project/Area Number |
20H02024
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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 18010:Mechanics of materials and materials-related
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| Research Institution | Kanazawa University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
新山 友暁 金沢大学, 機械工学系, 准教授 (00583858)
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| Project Period (FY) |
2020-04-01 – 2023-03-31
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| Keywords | 疲労破壊 / 界面 / 転位 / 分子動力学法 |
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| Outline of Final Research Achievements |
This research was conducted using molecular dynamics to study the interaction between the “heterophase interface” and “persistent slip band (PSB)” under cyclic loading, and attempted to elucidate the formation mechanism of the embryo (starting point of nucleation) of fatigue failure caused by the superimposed phenomena of dislocation penetration, decomposition, and passage at the heterophase interfaces. First, it was shown that the interface functions as an absorption site for dislocations, and thus the dislocation density decreases with cyclic deformation, resulting in a grain-size dependence of the dislocation microstructure. Next, a PSB model was developed, and it was shown that when screw dislocations moving in a channel region under cyclic deformation penetrate the interface, the dislocations are not re-emitted from the interface even when loading occurs in the reverse direction, and the interface has a strong influence on the formation of fatigue fracture embrittlement.
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| Free Research Field |
計算材料力学
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| Academic Significance and Societal Importance of the Research Achievements |
本研究では，未だ解決していない人類の普遍的課題の一つである疲労破壊に対する界面の役割，特に，固執すべり帯を構成する転位壁に平行な方向に存在する界面と転位の相互作用を原子シミュレーションを用いて明らかにしたことが最大の成果である．また，この成果は，疲労現象におけるサイズ効果（粒径依存性）や界面構造の影響に対して新たな知見を与えるものであり，今後の疲労破壊の本質的な理解に貢献することが強く期待される．
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