High temperature performance of PbTiO3/PZT ultrasonic transducer above 400°C

A 100μm thick PbTiO₃ (PT)/ Pb(Zr,Ti)O₃ (PZT) sol-gel composite film was fabricated on a 3mm thick titanium substrate by spray coating technique. After PT/PZT film fabrication, the substrate was tested in a furnace from room temperature to 500 °C for the maximum operation temperature verification. It was found that ultrasonic response with reasonable signal to noise ratio (SNR) was obtained from room temperature to 430 °C, though signal amplitude reduced drastically above 400°C. Thermal cycle test and continuous monitoring test were operated and as a result, the performance of the PT/PZT sol-gel composite ultrasonic transducer showed higher sensitivity than that of bismuth titanate (BiT/PZT) and sufficient thermal durability. Therefore, PT/PZT could be a good candidate as ultrasonic transducers for non-destructive testing (NDT) at 400°C.