| Project/Area Number |
06302035
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| Research Category |
Grant-in-Aid for Co-operative Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
機械工作・生産工学
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| Research Institution | Toyota Technological Institute |
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Principal Investigator |
SATA Toshio Toyota Technological Institute, Faculty of Engineering, Professor, 工学部, 教授 (80010594)
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| Co-Investigator(Kenkyū-buntansha) |
KITAGAWA Hiroshi Osaka University, Faculty of Engineering, Professor, 工学部, 教授 (30029095)
INAMURA Toyoshiro Nagoya Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (60107539)
NAKAGAWA Takeo Institute of Physical and Chemical Research, Chief Scientist, 主任研究員 (40013205)
SHIMADA Soichi Osaka University, Faculty of Engineering, Associate Professor, 工学部, 助教授 (20029317)
IKAWA Naoya Osaka University, Faculty of Engineering, Professor, 工学部, 教授 (60028983)
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| Project Period (FY) |
1994 – 1995
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| Project Status |
Completed (Fiscal Year 1995)
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| Budget Amount *help |
¥20,300,000 (Direct Cost: ¥20,300,000)
Fiscal Year 1995: ¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1994: ¥12,900,000 (Direct Cost: ¥12,900,000)
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| Keywords | Brittle materials / Nanometer-machining / Ductile-brittle transition / Indentation / Cutting / Grinding / Molecular Dynamics / Finite Element Method / 延性脆性遷移現象 |
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| Research Abstract |
To understand the mechanisms of ductile mode material removal at small depth of cut and the transition in material removal from brittle to ductile in machining of brittle materials, experimental studies on micromachining of various brittle materials and molecular dynamics (MD) computer simulations on microcutting of defect free monocrystalline silicon are carried out.
Mophological observations of worksurfaces machined by diamond turning and ELID griding under various machining conditions by optical microscope, SEM and AFM show that any brittle material, regardless of their intrinsic brittleness, can be machined in pure ductile mode under a sufficiently small size of unit process (corresponding to uncut chip thickness in turning, grain depth of cut in grinding). Usefulness of microindentation testing and single point scratch testing with continuously increasing of depth of cut is demonstrated for the evaluation of intrinsic brittleness or ductility and critical size of unit process for d
… More
uctile mode machining of individual materials.
MD simulations suggest that the critical depth of cut can be governed by the amount of energy of elastic waves generated in cutting zone as the results of release of potential energy stored in workpiece by the plowing of cutting edge. "Renormalized MD" simulation, in which the concept of "renormalization" is combined with conventional MD simulation, is proposed so that MD can be applied to various size of unit proces ranging from nanometer to micrometer scale. The results of renormalized MD simulations on microcutting of silicon under the uncut chip thickness from 1 nm to 1 mm show that chip removal is performed in ductile mode even at 1 mm uncut chip thickness. However, by incorporating the effect of chemical adsorption of atomospheric gas and/or liquid on cutting tool and workpiece, which was not considered in conventional MD simulation, the brittle-ductile transition phenomena can be observed. The result suggests that there must be some additional mechanism such as chemical adsorption of atomospheric gas and/or liquid in brittle-ductile transition in material removal process of brite materials. Less
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