Control of pore size and wall thickness of 3-1 type porous PZT ceramics during freeze-casting process

Highlights: • A comprehensive control of pore size and wall thickness in piezoceramic honeycombs. • The effects of pore size and wall thickness on piezoelectric properties also have been studied. • The process parameters for microstructure adjusting during freeze-casting can be applied to other ceramics. 3-1 type porous lead zirconate titanate (PZT) ceramics with unidirectionally aligned pore channels were prepared by freeze-casting process of which the freezing temperature was varied at − 10 ~ − 100 °C, and the solid content of slurries was changed at 15 ~ 40 vol%. Characterization of pore size distributions and wall thickness distributions demonstrated the freezing temperature significantly influenced the pore size and wall thickness, while the solid content had strong influence on the porosity. When the solid content was stationary, the pore size decreased with decreasing freezing temperature and the wall thickness also tended to decrease. When the freezing temperature was constant, the porosity decreased as the initial solid content increased, meaning decreased ratio of pore size and wall thickness. The fabricated samples exhibited high piezoelectric coefficient and there was a trend that it increased with the simultaneous decrease of pore size and wall thickness.