Fatigue failure characteristics of lead zirconate titanate piezoelectric ceramics

Mechanical properties and fatigue failure characteristics of lead zirconate titanate piezoelectric ceramic (PZT) have been investigated. Bending and fatigue strengths of PZT ceramic are directly attributed to the electrode status. Material hardening occurs in the PZT ceramic during the cyclic loading, which is influenced by domain switching occurring anywhere in the grains. The domain structure is clearly detected by electron back scatter diffraction analysis and etching techniques. It also appears that the poling direction causes the change of failure characteristics due to different domain and domain wall orientation. The domain orientation changes alternately from domain to domain by 90°. Moreover, the domain wall orientation is well regulated in the grains perpendicular to the poling direction. An acceleration of fatigue crack growth occurs as the crack propagates along the domain wall.