2015 Fiscal Year Final Research Report
Improvement of fatigue property by laser peening and investigation of fatigue fracture mechanism with synchrotron radiation on friction stir welding joints
Project/Area Number |
25420741
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Composite materials/Surface and interface engineering
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Research Institution | Okinawa National College of Technology |
Principal Investigator |
MASAKI KIYOTAKA 沖縄工業高等専門学校, 機械システム工学科, 准教授 (30323885)
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Research Collaborator |
SANO Yuji
KAJIWARA Kentarou
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Project Period (FY) |
2013-04-01 – 2016-03-31
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Keywords | 摩擦攪拌接合 / 放射光ラミノグラフィ / 疲労き裂進展 / 応力拡大係数 / レーザピーニング / ショットピーニング |
Outline of Final Research Achievements |
In this study, the fatigue fracture mechanism of the friction stir welding (FSW) joints of aluminum alloy, which had been applied to various types of transportation equipment, were investigated. And, in order to improve the plane bending fatigue property on FSW joints of aluminum alloy, the laser peening without coating treatment and the shot peening treatment with zirconia shot were applied to FSW joints. At first, we established the laminography technique with synchrotron radiation of SPring-8 for observation of the fatigue crack in FSW joints. The three-dimensional shape of the fatigue crack and the friction stirred microstructure in the FSW joints were visualized by the laminography technique. Furthermore, we indicated that the fatigue property of the FSW joints of aluminum alloy was able to improve by the laser peening without coating or the shot peening. In addition, we suggested that mild peening conditions were suitable in order to obtain a high fatigue improvement effect.
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Free Research Field |
工学
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