Piezoelectric ceramic materials for power ultrasonic transducers

The active material of power ultrasonic transducers is a ferroelectric ceramic. The methods of characterization of these materials from resonance are a key issue in the transducer design. Worldwide, regulations require lead zirconate titanate (PZT) piezoceramics to be substituted due to the hazards of PbO at the processing and lifetime of these materials. The main “lead-free” families are bismuth-layered structure ferroelectrics, solid solutions based on alkaline niobates (KNbO3-NaNbO3 or KNN), and those based on bismuth sodium titanate (Bi0.5Na0.5TiO3 or BNT). New compositions and oriented grain ceramics are also under study. To date, there is not a direct replacement for PZT; however, the most appropriate lead-free composition is available for each application and the generalized commercialization of these materials is envisaged. © 2023 Elsevier Ltd. All rights reserved.