Microstructure and Electrical Properties of Porous PZT Ceramics with Unidirectional Pore Channel Structure Fabricated by Freeze-casting

摘要

By a novel freeze-casting technique, PZT ceramics with unidirectional pore channel structure were fabricated using tert-butyl alcohol (TBA) as pore forming template, PVB as adhesive, and arabic gum as dispersing agent. The solid loading in the initial slurry varied from 15 vol.% to 40 vol.%. The porous structure can be controlled by the freezing temperature condition which was chosen by dry ice (-78°C). The sintered PZT ceramics with a high porosity showed high piezoelectric coefficient. The d_(33) value of some samples with the porosity 26% was larger than the dense PZT ceramics which was 690 pC/N. Meanwhile, pore morphology of the porous PZT ceramics was observed with SEM and analyzed changing with the solid loading of PZT in slurry. In addition, the influences of solid loading in PZT slurry on piezoelectric and dielectric properties of the porous PZT ceramics were discussed from a theoretical perspective.