2021 Fiscal Year Final Research Report
Mechanism investigation and modeling of material deformation enhancement in micro forming with vibration energy assistance
| Project/Area Number |
19H02481
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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 | Tokyo Metropolitan University |
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Principal Investigator |
Yang Ming 東京都立大学, システムデザイン研究科, 教授 (90240142)
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| Co-Investigator(Kenkyū-buntansha) |
清水 徹英 東京都立大学, システムデザイン研究科, 准教授 (70614543)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Keywords | マイクロ金属加工 / 超音波振動 / 素材変形促進 / SEM-EBSD分析 / モデル化 |
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| Outline of Final Research Achievements |
A high-frequency response force sensor was introduced to enable the separation of various effects such as stress superposition, acoustic softening and impact by real-time measurement of the contact state between the punch and the material during ultrasonically assisted forming. In addition, SEM-EBSD analysis was applied to investigate structure of the deformed specimens. It is found that the acoustic softening can reduce the dislocation density and randomize the dislocation distribution、 and it increases dislocation mobility、 leads to dynamic recovery and dislocation annihilation. A constitutive model for prediction of the flow stress incorporating the dislocation transfer promotion of crystalline materials was proposed based on the experimental results. The prediction results was compared with the experimental results of Al and Cu. The estimation results by the constitutive model showed good agreement for different materials and amplitudes.
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| Free Research Field |
マイクロ金属加工
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| Academic Significance and Societal Importance of the Research Achievements |
従来研究で、ブラッハ効果として評価解釈されてきた応力重畳と音響軟化を分離し、個々の変形メカニズムに適した理論モデルを構築した。素材の動的な変形挙動をオンラインモニタリングし、現象の解析、および各種効果の定量的な評価に基づいた理論モデル構築は、超音波振動援用技術における複雑性を解決する点で大きく貢献する。
従来から超音波振動の効果を塑性加工に応用することが試みられてきた。超音波振動援用マイクロ塑性加工プロセスの確立は加工精度の向上や素材の成形性向上効果が大きく、実用化が期待されている。超音波振動の各種効果と素材の変形に結び付ける理論式の提案により、その実用化が促進され、波及効果が大きい。
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