| 摘要 |
PROBLEM TO BE SOLVED: To achieve high-sensitivity flaw detection and at the same time eliminate the need for generating unneeded echoes by arranging a plurality of vibration elements at a wedge for oblique-angle flaw detection in an array and setting a vibration element opening width being determined by the width and interval of the elements with a specific expression. SOLUTION: Ultrasonic flaw detection is made, for example, by using an oblique- angle array probe 4 with (n) vibration elements 1 being arranged at a constant interval on the inclined surface of a wedge 2, and each element 1 is individually excited by (n) pulsers included in a group of pulsers 5. A vibration element opening width D in the inclination direction of the wedge is set so that an expression can be satisfied by setting the inclination angle of ultrasonic waves on the flaw detection surface of a specimen to α: a refractive angle to θ; a beam distance determined by an oblique angle flaw detection range or the target position of oblique angle flaw detection to L; wavelength in the nominal frequency of the vibration element of ultrasonic waves being propagated in the specimen to λn. Also, in the plurality of elements 1, the excitation timing and the synthesis timing of a reception signal are controlled for each element, thus performing control so that an ultrasonic sound field being formed in the specimen becomes a desired shape. |
