| Project/Area Number |
10555025
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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 | 展開研究 |
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| Research Field |
Materials/Mechanics of materials
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| Research Institution | Tohoku University |
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Principal Investigator |
SOYAMA Hitoshi Tohoku University Graduate School of Engineering Associate Professor, 大学院・工学研究科, 助教授 (90211995)
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| Co-Investigator(Kenkyū-buntansha) |
URANISHI Kazuo DMW Corporation, Mishima Plant, Department of Design, Chief, 三島事業所, 設計部部長(研究職)
WATANABE Yutaka Tohoku Univirsity Graduate School of Engineering Associate Professor, 大学院・工学研究科, 助教授 (10260415)
ITO Takatoshi Tohoku Univirsity Institute of Fluid Science Associate Professor, 流体科学研究所, 助教授 (00184664)
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥6,100,000 (Direct Cost: ¥6,100,000)
Fiscal Year 2000: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1999: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1998: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Surface Modification / Impact / Residual Stress / Corrosion Resistance / Cavitation / Jet / Fatigue Strength / Peening / ノズル / ショットピーニング / 最適加工速度 / 寸法効果 |
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| Research Abstract |
1.Surface modification system has been developed considering scale effects of nozzle diameter. Diameter of nozzle is from 0.4mm to 1.9mm.
2.Cavitation impacts were measured by a PVDF transducer for various cavitating conditions. When the nozzle diameter was increased, the frequencies of the cavitation impacts were not only increased but also the intensity of the cavitation impacts increased. Reducing air contents ration in the test water also increased the cavitation impacts.
3.Optimum peening time or optimum scanning speed was demonstrated by measuring hardness or residual stress. The cavitating jet can introduced compressive residual stress in the surface of the materials. The value of the compression was saturated at certain processing time or speed. In case of the improvement of the corrosion resistance by using a cavitating jet, optimum processing time was obtained by the relation between the potential by means of an electrochemical method and the processing time.
4.Regarding test liquid of the cavitating jet, several liquids ware tested changing with pH.Suitable test liquids for iron were clarified referring Pourbaix diagram of iron.
5.Peening for gears and specimens with a notch was carried out. It was revealed that the peened surface by a cavitating jet was very smooth comparing with that of the shot peening. The cavitating jet can also introduce the compressive residual stress into hard materials such as tool alloy SKD61.
6.In order to demonstrate improvement of fatigue strength by suing a cavitating jet, a rotating bending fatigue test was carried out. It was shown that the cavitating jet could improve the fatigue strength. It was also revealed that the cavitating jet could improve the corrosion resistance about 30% by means of an electrochemical method.
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