Abstract
Underwater characterizations of (Pb0.94Sr0.04)(Zr0.52Ti0.48)O-3 (PZT) and PZT/araldite-F 1-3 composite were carried out through a self-designed transducer. Disc-shaped samples of bulk PZT and PZT/araldite-F composite were first characterized in air and then were assembled in the transducer individually. The transducer's underwater voltage receiving sensitivity (S-h) and transmitting voltage response (S-v) were investigated in the frequency range of 10-200 kHz (well below thickness mode resonance) using a calibrated projector and receiver method with pulse technique. Results revealed that the transducer made with composite sample exhibited better S-h values (-214 dB ref 1 V/mu Pa) due to similar to 295% higher piezoelectric voltage coefficient g(h) (30x10(-3) Vm/N) of the composite compared to PZT. In addition, the transducer with the PZT sample showed better S-v values (80 dB ref 1 mu Pa/1 V at 1 m) due to the presence of planar mode peaks in the frequency range of 10-200 kHz. These results indicate that the monolithic piezoceramic can exhibit underwater S-v response in both planar and thickness resonance modes owing to the admittance peaks in these frequency regions.