Piezoelectric Properties of a Pioneering 3-1 Type PZT/Epoxy Composites Based on Freeze-Casting Processing

摘要

Lead zirconate titanate (PbZr_(1-x)Ti_xO_3, PZT)/epoxy composites with one- dimensional epoxy in PZT matrix (called 3-1 type piezocomposites) have been fabricated by tert-butyl alcohol (TBA)-based directional freeze casting of PZT matrix and afterward infiltration of epoxy. The composites with PZT volume fraction ranging from 0.36 to 0.69 were obtained by adjusting initial solid loading in freeze-casting slurry. The effect of poling voltage on piezoelectric properties of the composites was studied for various volume fraction of PZT phase. With the increasing of PZT volume fraction, relative permittivity (ε_r) increased linearly and piezoelectric coefficient (d_(33) and d_(31)) increased step by step. The resultant composites with 0.57 PZT volume fraction possessed the highest hydrostatic piezoelectric strain coefficient (d_h) value (184 pC/N), voltage coefficient (g_h) value (13.6 × 10~(-3) V/m Pa), and hydrostatic figure of merit (HFOM) value (2168 × 10~(-15)_ Pa~(-1)).