Destruction mechanism of multilayer ceramic actuators: Case of antiferroelectrics

Abstract

In order to investigate destruction mechanism of crack propagation in multilayer ceramic actuators of antiferroelectric Pb0.99Nb0.02[(Zr0.7Sn0.3)0.955Ti0.045]0.98O3 with an interdigital electrode configuration has been observed dynamically under cyclic electric fields using CCD microscopy. The accompanying characteristics of the induced displacement and acoustic emission during crack propagation were measured simultaneously. Crack initiated slightly inside the edge of the internal electrode and propagated along the center area between electrode pairs, which differed markedly from the case of a piezoelectric actuator which displacement was proportional to the applied electric field. During the crack propagation process, the induced displacement of the multilayer actuator doubled in size, and the acoustic emission count increased remarkably. The effect of layer thickness on the destruction process has also been investigated. Reducing the layer thickness of the ceramic actuator, toughness of the actuator was improved.