Crack propagation behavior in lead zirconate titanate-based ferroelectric ceramics

In this study, Vickers indentation was utilized to characterize the crack propagation anisotropy of Nb/Ce co-doped Pb(Zr0.52Ti0.48)O-3 (ab. PZT-NC) ceramics in different media environments and under varying temperatures. Three-point bending associated with Weibull statistics was used to further evaluate the fracture properties. The results demonstrate that PZT-NC ceramics have the best fracture toughness in silicone oil and the worst in air. The fracture toughness and flexural strength of poled PZT-NC ceramics have significant anisotropy due to ferroelastic toughening (K-sh) with crack propagation. Parallel to the poling direction, the fracture toughness and reliability of the flexural strength of poled PZT-NC ceramics are higher. As the temperature increases (from 25 degrees C to 205 degrees C), the fracture toughness of PZT-NC ceramics dramatically decreases, which is attributed to the decrease in ferroelastic switching (K-sh).