2013 Fiscal Year Final Research Report
Effect of crack growth on changes in microtesla magnetic field of tool steel
Project/Area Number |
23560089
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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 |
Materials/Mechanics of materials
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Research Institution | University of Toyama (2013) Kyushu University (2011-2012) |
Principal Investigator |
KIDA Katsuyuki 富山大学, 大学院理工学研究部(工学), 教授 (00271031)
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Project Period (FY) |
2011 – 2013
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Keywords | 疲労 / 非破壊検査 / 塑性変形 / 破壊 / き裂 / 磁場 / プローブ顕微鏡 |
Research Abstract |
Damage of machine components occurs when cracks form and grow to a size large enough to cause fracture. In order to understand the crack propagation phenomena, non-destructive evaluation methods that can be correlated to measurements around the fatigue crack tips are necessary. In the present work, a scanning Hall probe microscope (SHPM) equipped with a three-dimensional sensor was developed and magnetic fields around fatigue cracks at room temperature were observed in air. The area around the crack tip was magnetized and the changes in the area were observed. The changes in magnetic fields in soft and hard specimens with the same intensity factors were compared. Furthermore, Vickers indentations in as-received tool steel plates were induced and the relation between magnetic fields and the plastic deformation sizes was observed. A strong correlation between the changes in the magnet fields and plastic deformation areas was found.
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