Significantly decreased depolarization hydrostatic pressure of 3D- printed PZT95/5 ceramics with periodically distributed pores
Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics with porous structure of periodic distribution were fabricated successfully via Direct Ink Writing, a type of 3D printing technique. The effect of periodically distributed porous microstructure on the dielectric, ferroelectric, as well as hydrostatic-pressure-induced depolarization properties of PZT95/5 ferroelectric ceramics, was investigated. The printed porous ceramics exhibit relatively good viscoelasticity to retain the periodic structure during 3D printing and drying. In contrast with dense PZT95/5 ferroelectric ceramics prepared by conventional solid-state sintering, low bulk density of the periodically distributed porous PZT95/5 ceramics leads to a decreased remanent polarization of 22.9 µC/cm2 under 2 kV/mm. As the hydrostatic pressure increased, the poled periodically distributed porous PZT95/5 ceramics depolarize sharply under a low and narrow hydrostatic pressure range of 113–116 MPa with a released charge density of 23.9 µC/cm2, while the poled dense PZT95/5 ceramics depolarize under a range of 250–278 MPa. Therefore, the introduction of periodically distributed micropores into PZT95/5 ceramics decreases the ferroelectric-to-antiferroelectric phase transition hydrostatic pressure significantly and maintained relatively excellent other properties simultaneously, such as temperature stability and low dielectric loss. The almost sharp depolarization behavior under a significantly decreased hydrostatic pressure demonstrates that periodically distributed porous PZT95/5 ferroelectric ceramics fabricated controllably by 3D printing exhibit excellent performances and prospects in mechanical–electrical energy conversion applications.