LASER ULTRASONIC FLAW DETECTION METHOD AND APPARATUS

摘要

A laser beam for ultrasonic generation is emitted to a reflector/vibrator to generate an ultrasonic wave, and the ultrasonic wave is transmitted to an object to be inspected. The ultrasonic wave transmitted to the object is reflected at a flaw inside the object, returns to the reflector/vibrator and vibrates it. The vibration is detected using a laser beam for ultrasonic detection to find flaws inside the object. According to the present invention, ultrasonic flaw detection can be made for reflecting materials having corrugations on their surface or having a low reflection factor of light, and for objects made of materials which cannot easily generate the ultrasonic wave by the laser beam. For such materials, the conventional method has not been useful because it adopts the direct application of the laser beam to the surface of the object to generate the ultrasonic wave.