| Budget Amount *help |
¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2013: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2011: ¥1,950,000 (Direct Cost: ¥1,500,000、Indirect Cost: ¥450,000)
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| 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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