Improvement in the Identification of a Crack Tip Echo in Ultrasonic Inspection using Large Displacement Ultrasound Transmission

As an improvement in the imaging technique for the low S/N ratio of crack tip echo in ultrasonic inspection, we developed the Subharmonic Phased Array Crack Evaluation (SPACE) system. Although the pulser of conventional SPACE can generate large, over tens of nm, displacement ultrasound at a crack, it is effective only for closed cracks and not effective for most industrial cracks. For general use of the SPACE system in industrial inspection, we need to develop larger displacement ultrasound incidence equipment considering crack openings of the order of several nm to sub it m. In this study, we developed a high voltage excitation SPACE and larger amplitude ultrasound incident to a crack using a high voltage proof transducer. The suitability of the developed system was investigated using typical models of cracks.