| Project/Area Number |
17560092
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Production engineering/Processing studies
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| Research Institution | Ibaraki University |
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Principal Investigator |
SHINOZUKA Jun Ibaraki University, college of Engineering, Lecturer, 工学部, 講師 (30282841)
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| Project Period (FY) |
2005 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2006: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2005: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Keywords | Ultra high-speed cutting / Plastic shock wave / Machined surface / Cutting circumstance / Cutting environment / Cutting tester / Chip / Cutting force / 塑性波 / 衝撃波 / 高性能表面 / 切削温度 / 静水圧 |
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| Research Abstract |
When cutting speed exceeds plastic speed of a workpiece, plastic shock waves are generated and inducing high level of hydrostatic stress at the shear zone. Since high level of hydrostatic stress can cause the dynamic recrystallization, the phase transformation and the refining of crystal grain, high performance machined surface can be obtained with ultra high-speed cutting. This research aimed to clarify the cutting mechanism under ultra high-speed cutting and to examine the possibility of generating a high performance machined surface with ultra high-speed cutting. A cutting tester was developed to examine ultra high-speed cutting mechanism by cutting experiment. And a FEM cutting simulator considering Drucker-Prager yield criterion was developed to investigate influences of high level of hydrostatic stress on cutting mechanism. The cutting tester can control cutting environment. It has an accelerating tube of 3m in length, a chamber in where a workpiece is placed and a decelerating tube of 3m in length. A small projectile with built-in a small cutting tool loaded into the accelerating tube is accelerated with a compressed air. High-speed cutting is achieved in the chamber. A piezoelectric dynamometer is placed under the workpiece to measure cutting forces and two fiber optic sensors are set in the chamber to measure the speed of the projectile. Chip is captured in the projectile. After finishing cutting, the projectile is decelerated and stopped with a compressed air. In the design specification, cutting speed reaches 280m/s when the pressure of the compressed air for launching is 0.9MPa. From the FEA, it is seen that high level of hydrostatic stress is generated at cutting edge regardless of cutting speed in case of Drucker-Prager yield criterion since bulk strain increases with plastic strain in case of the criterion. This may become a clue of the clarification of the built-up edge generation mechanism.
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