| 摘要 |
PROBLEM TO BE SOLVED: To provide a stress evaluation method and system by surface acoustic wave which can efficiently evaluate stress caused inside a magnetic body by utilizing a leaked oscillating magnetic field caused by transmitting surface acoustic wave on the magnetic body surface. SOLUTION: On the surface of a magnetic substance object 20 to be measured, ultrasonic wave W<SB>0</SB>from an ultrasonic vibrator 11a is introduced with a specific incident angle and the surface acoustic wave W is transmitted and a bias magnetic field is impressed in the transmitting direction of the surface acoustic wave W with a coil 12 for impressing magnetic field. The leaked oscillating magnetic field on the magnetic body surface is measured as an induced electromotive force with a detection coil 13 by the inverse magnetostrictive effect of the surface acoustic wave W. By reversing the transmission direction of the surface acoustic wave, the induced electromotive force is similarly measured and the stress existing in the magnetic substance is evaluated from the difference in the induced electromotive forces due to the difference in transmission directions. COPYRIGHT: (C)2007,JPO&INPIT
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