Compositional Dependence of R‐curve Behavior in Soft Pb(Zr1−xTix)O3 Ceramics
The compositional dependent fracture behavior of soft PZT (Pb0.99Ba0.01(Zr1−x
)0.98Nb0.02O3) ceramics in the vicinity of
the morphotropic phase boundary was characterized using compact‐tension specimens. The compositions with 0.40 ≤ x ≤ 0.55 displayed an increasing fracture resistance with crack extension (R‐curve behavior). It was observed that the
rhombohedral composition and the compositions near the morphotropic phase boundary showed the largest toughness enhancement. R‐curve behavior was found to be influenced by the ferroelastic coercive stress, saturated remanent strain, and elastic modulus, which
were experimentally measured for each composition. X‐ray diffraction measurements were performed and compared to the fracture results to investigate the impact of phase and lattice distortion on ferroelastic toughening behavior.