Research On 1-3 Series Piezoelectric Composite And Underwater Transducer

The structure, fabrication technics, measurement technique, theoretical model and resonance performance of 1-3 type and its modified type (all named 1-3 series) piezocomposites are researched in the dissertation. The transducers and arrays are developed by using 1-3-2 type piezoelectric composite.1-3-2 piezocomposite is composed of 1-3 composite part and ceramic substrate in structure. The fabricating technics for 1-3 series composites by dice-filled technique are studied. The techniques used for sputtering electrode on the surfaces of composites are investigatied, and the process flow is established. The several kinds of metal film are covered on the surfaces of composite samples. The properties of the thin film are tested.The methods used to measuring the material properties of 1-3 series composites are presented, and the performance of the composite samples is investigated. The stability of composite properties with environment temperature and pressure are researched, and the mesearment result shows that the performance of 1-3 series piezocomposite posses good stability while the environment temperature and pressure are changing.The theoretical model of 1-3-2 piezocomposite is established based on the linear piezoelectric theory and uniform field theory. The theoretic relations between effective parameters and volume fractions of piezoceramic in 1-3-2 composite are deduced. The effective properties of two type piezocomposite are calculated. The data calculated by the model are compared with that by experiments, and the results indicate that the calculation is good agreement with experiment.The influence of piezoelectric phase volume fraction and composite aspect (thickness/width) on resonance characteristic of the square 1-3-2 piezoelectric composite plate is researched. Some 1-3-2 composite samples are fabricated, and the resonance frequency of samples is investigated. The range of thickness/width that causes single thickness vibration of 1-3-2 composite plate is gained.The underwater acoustic transmitting and receiving transducers are developed by using 1-3-2 type piezoelectric composite. Their structure and fabricating techniques are studied. The properties of transducers and arrays, such as transmitting voltage response, receiving voltage sensitivity and directivity are investigated.