Mechanics, tribological characterization and Scale effect in ultra-high pressure hydroforming of micro-tubes
| Project/Area Number |
18K04781
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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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 |
Ken-ichi Manabe 東京都立大学, システムデザイン研究科, 客員教授 (10145667)
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| Co-Investigator(Kenkyū-buntansha) |
高橋 智 東京都立大学, システムデザイン研究科, 准教授 (80260785)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2019: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2018: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| Keywords | マイクロ金属加工 / 長尺マイクロチューブ / マイクロトライボ特性 / 材料流動特性 / 成形メカニズム / 寸法効果 / 高液圧成形 / 枝管成形 / マイクロチューブ / マイクロトライボ機構 / 成形不良 / 超高圧成形 / トライボ特性 |
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| Outline of Final Research Achievements |
In micro T-shape forming using micro tubes with 0.5 mm outer diameter, it was confirmed quantitatively that the effects of tube length L and friction coefficient μ on hydroformability are qualitatively equivalent, which is generally understood that longer tubes and higher show lower hydroformability. Also, as a factor affecting the material flow of the tube from the theoretical model, it was derived that it does not depend on the L, but on the μ and the surface contact pressure p on the die, and on the strength, outer diameter and wall thickness of the tube material.
Also, it was clarified that a heterostructure expressing material inhomogeneity easily causes local defective deformation of the microtube as the size effect using an inhomogeneous finite element model that considers the distribution of grain size and deformation resistance. Also, it was shown that the heterostructure affects the material flow / deformation behavior and hydroformability.
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| Academic Significance and Societal Importance of the Research Achievements |
マイクロ金属管の液圧成形性が低いメカニズムをその材料流動性に着目して力学的に影響因子を解明した学術的意義は大きい。具体的に軸押しによる管の流動域長さが管の長さに依存せず、摩擦係数、金型内面の面圧、管材の強度と外径と肉厚の関数で定式化したことに意義があり、超高圧力負荷は材料流動促進には逆効果になる場合もあることも導いた。結晶粒を考慮した不均質有限要素モデルから局所的材料変形の誘因となる寸法効果を明らかにした点も学術的意義が高い。
また、微細結晶粒などのマイクロ管を用いることや最適成形条件の指針を提示できたのは、長尺管のマイクロ液圧成形への可能性の道を拓いた点で社会的意義は大きい。
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Report
(4 results)
Research Products
(11 results)
