JPS6475962A - Ultrasonic flaw detection apparatus - Google Patents

Abstract

PURPOSE:To detect a flaw at a high speed with high sensitivity, by providing a partition plate made of an acrylic resin set to an angle range of 35-55 deg. with respect to the advance direction of ultrasonic beam and an ultrasonic wave absorbing material on the ultrasonic wave propagation route between an ultrasonic probe and a material to be inspected. CONSTITUTION:A partition plate 6 made of an acrylic resin having a uniform thickness is provided on the part of the acoustic coupling material 3 between a material 1 to be inspected and an ultrasonic probe 2 so as to be set to an angle range of theta=35-55 deg. with respect to the advance direction of ultrasonic beam 5. Herein, the beam 5 generated from the probe 2 is reflected by the partition plate but, with respect to the level of the reflected wave from the partition plate 6, the reflectivity thereof becomes about 10% or less within the angle range of theta=35-55 deg.. However, in high sensitivity flaw detection, the reflection level of the ultrasonic beam becomes a noise level not yet neglected to become a cause for lowering flaw detection capacity and, therefore, by providing an ultrasonic wave absorbing material 7 to the side surface where the ultrasonic beam reaches through the partition plate 6, the ultrasonic beam can be absorbed and attenuated to make high sensitivity flaw detection possible.