Fabrication of angle beam two-element ultrasonic transducers with PMN–PT single crystal and PMN–PT/epoxy 1–3 composite for NDE applications

The paper describes the fabrication of angle beam two-element prototype ultrasonic transducers with PMN–PT single crystal and PMN–PT/epoxy 1–3 composite. The optimal designs of transducers were obtained based on the simulation of PiezoCAD software. A two-layer front matching structure for PMN–PT single crystal transducer and a one-layer front matching structure for PMN–PT/epoxy 1–3 composite transducer were selected to match the polyimide slopping block. In the detection on the stainless steel reference block, PMN–PT single crystal and commercial PZT-based 1–3 composite transducer show similar performances in sensitivity and bandwidth, and PMN–PT/epoxy 1–3 composite transducer shows the best performances. The two-way insertion loss and bandwidth at −6 dB of the PMN–PT/epoxy 1–3 composite transducer are −21.3 dB and 94.5%, respectively.