2000 Fiscal Year Final Research Report Summary
Development of a New Ultra-precision Finishing Process Applying the Cavitation Phenomena in Ultrasonic Vibration
| Project/Area Number |
11650116
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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 |
機械工作・生産工学
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| Research Institution | Utsunomiya University |
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Principal Investigator |
SHINMURA Takeo Utsunomiya University Graduate School of Engineering Professor, 大学院・工学研究科, 教授 (30008049)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAGUCHI Hitomi Utsunomiya University Faculty of Engineering Associate Professor, 工学部, 助教授 (40282595)
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| Project Period (FY) |
1999 – 2000
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| Keywords | Ultrasonic cavitation / Fine machining / Magnetic abrasive finishing / Ultra precision machined surface / Stock removal / Surface roughness |
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| Research Abstract |
This research proposes a new ultra-precision finishing process in which the motion of the abrasive is controlled by cavitation caused by ultrasonic vibration in distilled water mixed with abrasive. The abrasive accumulates onto the surface of the workpiece and shows microscopic vibration by cavitation based on the ultrasonic vibration. This must remove the material from the surface the workpiece. To realize the above-mentioned principle, an experimental setup, which consists of an ultrasonic oscillator, electrostrictive vibrator (l8kHz frequency, 400 W output), vibration amplifying horn, and tool, was developed. The tool made of SUS3O4 stainless steel was mounted onto the tip of the horn. The workpiece was set into a container with distilled water and the abrasive under the horn. The ultrasonic vibration was imparted vertically to the target surface of the workpiece. The machining characteristics were experimentally investigated using the developed setup. A C3604 brass plate (□20×5 mm) was used as a workpiece. The clearance between the horn tip and the target surface of the workpiece was varied from 0.5-2.0 mm. Machining characteristics identified from the experimental results were summarized as follows : (1) Although abrasive mixed into the distilled water helped to smooth the surface of workpiece, it prevented cavitation in the water. This resulted in a decrease of the machining efficiency. (2) The smaller the clearance between the tool tip and the target surface of the workpiece, the deeper was the machined depth because of the higher machining force by the enhanced cavitation. (3) Because of the concentration of the cavitation when the clearance was smaller, the machined geometry more closely followed the tool's geometry. This caused more effective machining at the center of the tool, generating a rougher surface at the center of the machining area than at the edge. (4) This process is applicable not only for micro-machining but also micro-edge finishing.
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