THE PROSPECTS FOR INTENSIFICATION OF SINTERING OF PIEZOCERAMIC MATERIALS

Abstract

The paper investigates the possibility of changing the properties of piezoelectric ceramics for various purposes.
The aim of the study is to correct properties by changing technological factors in the manufacture of
piezoceramics without modifying their chemical composition. At the most important technological stage – sintering
– the density, hardness and strength of piezoceramics are formed, which directly affect its electrophysical
parameters, since the piezoelectric effect is an Electromechanical transformation. Of particular interest are sintering
methods that combine the process of compaction of particles with heating - hot pressing and spark plasma
sintering. Such methods, due to the created uniaxial pressure, activate the diffusion processes of mass transfer
during sintering, contributing to the production of high-density piezoceramics while lowering the sintering temperatures. However, unlike hot pressing, spark plasma sintering generates spark discharges between the powder
particles, which, in combination with ultra-fast heating (up to 1000 ° C/min), forms a fine-grained monophase
structure of ceramics. This microstructure increases the mechanical and electrophysical parameters of the resulting
ceramics. The aim of the study was to test the proposed sintering methods on piezoelectric materials of different
compositions in order to control their properties. The objects of research were piezoceramic materials based
on the zirconate-titanate-lead system and their modifications, including multicomponent materials with high application
potential, as well as lead-free ferroelectric material Ba0.55Sr0.45TiO3 (BST). The dependences of the
formed ceramic structure on the sintering method and temperature were determined using scanning electron
microscopy. The regularities of "sintering method – microstructure – properties" are established. The effectiveness
of hot pressing and spark plasma sintering methods for correcting the properties of piezoceramics of various
types of applications has been confirmed, which together with a decrease in sintering temperatures, as well as a
reduction in the duration of the process (by 36 times!) relevant for energy saving purposes.