Short crack propagation behavior at electrode edge in PZT under cyclic electric loading

Short crack propagation behavior in poled lead zirconate titanate was examined under cyclic electric loading. A crack located at edge of a partial electrode grew along the electrode edge during the loading. The crack growth rate decreased with increasing crack length until a non-propagating crack was reached. The growth rate and crack length of the non-propagating crack were affected by the amplitude, mean voltage of the electric loading and environment. In the case of high-amplitude loading or negative-biased loading, the crack growth rate varied considerably because of domain switching. At testing temperature of 20 °C, moist atmosphere had no effect on the crack propagation behavior. However the crack growth rate fluctuated and non-propagating crack length was increased with increase in temperature to 40 °C. Finite element analysis of a three-dimensional permeable crack showed that the mode III stress intensity factor range is independent of crack length, but it decreases as a result of the frictional force under positive electric field. Fracture surface observations showed that intergranular cracking is dominant near the tip of the non-propagating crack. © 2013 The Japan Society of Mechanical Engineers.