Piezoelectric ceramic fibre/epoxy 1-3 composites for high-frequency ultrasonic transducer applications

Samarium and manganese doped lead titanate (PSmT) and lanthanum doped lead zirconate titanate (PLZT) fibres of 25–40 μm diameter have been prepared by the sol-gel methods. The sintered fibres were inserted into a plastic tube in a direction parallel to the tube axis. The tube was filled with epoxy and after the epoxy was cured, a 1-3 ceramic fibre/epoxy rod was formed. 1-3 composite disks were obtained by slicing the rod and they were then lapped to the required thickness and polarized. The properties of PSmT and PLZT 1-3 composites with various ceramic volume fractions were reported. High-frequency (20–50 MHz) composite transducers were fabricated and their pulse-echo response as well as frequency spectra were also measured and compared.