Investigation of high frequency (2.45 GHz, 30 GHz) processing of Pb-based piezoelectrics for ultrasound transducers

Microwave sintering of PZT based ceramics was investigated using multimode heating at 2.45 and 30 GHz and compared to conventional thermal processing. For PZT 5 and PZT 5H ceramics microwave processing resulted in a reduction of sintering temperature by more than 150°C. of significance to the production of high surface area lead-based components, minimal PbO volatility was detected for samples processed as high as 1200 °C. Microwave sintered fine scale 1-3 piezo composites prepared by the molding technique resulted in a thickness coupling coefficient of 56% and an acoustic impedance of 11.6 MRayls. Bandwidths of greater than 80% were modeled for optimally matched transducers.