Abstract
The paper describes the results of the experimental study of the properties of piezoceramics, ceramic matrix composites “ceramics/crystal,” and porous ceramics based on lead-free sodium-lithium niobates (Na, Li)NbO3 and sodium-potassium niobates (Na, K)NbO3 compositions. The measurements of elastic, dielectric and piezoelectric parameters, as well as microstructural studies of experimental samples of lead-free porous piezoelectric ceramics and composites were performed. It was shown that the use of alkali metal niobates in the form of ceramic matrix composites and porous ceramics allows to increase the main functional parameters of these materials and makes them competitive with piezoceramics of the PZT system. The developed lead-free porous and composite materials have a unique combination of parameters and can be used for the manufacture of ultrasonic transducers and devices for a wide range of applications, including medical and nondestructive testing equipment.