Fabrication of PIMNT/Epoxy 1-3 composites and ultrasonic transducer for nondestructive evaluation

In this paper, PIMNT/epoxy 1-3 composites with different volume fractions were prepared by the dice-and-fill method for application in ultrasonic transducers. The theoretical and experimental properties at different volume fractions and the temperature stability of the electromechanical property were investigated. The highest electromechanical coupling factor k_t was obtained as 0.833 with the volume fraction of 0.58 and k_t changed little below the Curie temperature of the single crystal. Afterward, an angle-beam transverse wave ultrasonic transducer using the fabricated composite was designed and manufactured based on the simulation of the KLM model and commercial software. The assembled prototype transducer showed large improvement in two-way insertion loss, relative bandwidth at -6 dB, surplus sensitivity, and axial resolution, which were -24.3 dB, 107%, 85 dB, and 28 dB, respectively, compared with a commercial PZT-based composite transducer.