Development of air-coupled low frequency ultrasonic transducers and arrays with PMN-32%PT piezoelectric crystals

Nowadays air-coupled ultrasonic techniques are increasingly used for non-destructive evaluation. The biggest problem is big losses of ultrasonic signals mainly due mismatch of acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is application of novel more efficient piezoelectric materials like PMN-PT type crystals. The objective of this research was development of wide band air-coupled ultrasonic transducers and arrays with an improved performance using PMN-32%PT crystals.