Dielectric, piezoelectric and elastic properties of PZT/PZT ceramic piezocomposites

A new method of PZT/PZT ceramic piezocomposites fabrication is proposed. Samples of piezocomposites with the volume fraction of components 0¿100% for different PZT compositions were fabricated and measured. A line of chemically, thermally, and technologically compatible PZT matrix and filling compositions were chosen. Different types of PZT type piezoceramics powders and pre-sintered piezoceramic granules were used as matrix and filling components respectively. The size and shape of the filling particles were chosen as a compromise between maximal scattering and minimal interfacial area to minimize chemical interaction between two composite phases. Special pressing and firing regimes were used for formation of microporous piezoceramic matrix. Sintering of the composites was carried out at special thermal profiles preventing cracking because of shrinkage and thermal expansion of composite components. Complex sets of elastic, dielectric, and piezoelectric parameters of piezocomposites were determined by ultrasonic and impedance spectroscopy method using piezoelectric resonance analysis (PRAP) software. Microstructure of polished, chemically etched, and chipped surfaces of piezocomposite samples was observed with optical and scanning electron microscopes. New PZT/PZT ceramic piezocomposites are characterized by a unique spectrum of the electrophysical properties unachievable for standard PZT ceramic compositions and fabrication methods and can be useful for wide-band ultrasonic transducer applications.