Microstructure characterization and properties of porous piezoceramics

Abstract

In this paper, a comprehensive study of microstructure/properties interrelations for porous piezoceramics based on PZT composition was performed. Experimental samples of porous piezoceramics were fabricated using a modified method of burning-out a pore former. Porosity dependencies of elastic, dielectric, piezoelectric and electromechanical coefficients of the porous ceramics in the relative porosity range 0–50% were obtained and analyzed. As a result of microstructure analysis, it was found that at any connectivity type (3–0, 3–3) and porosity up to 50% the real structures of porous piezoceramics were close to the matrix medium structure with continuous piezoceramic skeleton. It was also revealed that the microstructural features of porous piezoceramics define the character of the dependences of the dielectric, piezoelectric and electromechanical properties of porous piezoelectric ceramics on porosity. In conclusion, microstructure/properties interrelations, as well as new applications of porous piezoceramics were discussed.

The Fabrication and Characterization of BaTiO3 Piezoceramics Using SLA 3D Printing at 465 nm Wavelength

“…After compaction by pressing, such agglomerates do not allow dense packing of grains, and grain growth during the sintering is limited (Figure 15a). Grains of this size in BT ceramics [35] provide maximum values of the piezo module d 33 , exceeding 300 pC/N, and also may be caused by intensification of flex-tensional deformations [32]. This can explain the significant difference in the piezo module of the samples studied in this work.…”

“…These high losses could be attributed to the influence of moisture accumulated in open pores among the loose fine-grained matrix. With increasing porosity and internal surface, the domain walls fixation led to a decrease in loss tangent [32].…”

“…While the printed ceramics showed no obvious dependence of d 33 on the relative density, the traditional samples showed an increase in d 33 with reducing density. This result might be caused by intensification of flex-tensional deformations of the solid surrounded by the porous space under mechanical or electric influence [32]. The permittivity (measured at 1 kHz and room temperature) demonstrated values of 2355-2535 for traditional ceramics and 1695-2055 for the 3D-printed ones, with an exception of the most porous samples with low ε (Figure 12b).…”

“…While the printed ceramics showed no obvious dependence of d33 on the relative density, the traditional samples showed an increase in d33 with reducing density. This result might be caused by intensification of flextensional deformations of the solid surrounded by the porous space under mechanical or electric influence [32].…”

“…These high losses could be attributed to the influence of moisture accumulated in open pores among the loose fine-grained matrix. With increasing porosity and internal surface, the domain walls fixation led to a decrease in loss tangent [32]. the powder with the 60 min (BT-5) milling time due to the penetration of silver electrode paste into macrostructural inhomogeneities (i.e., cracks and large pores) during metallization (Figure 13).…”