Papers by Author: Jin Mei Du

Abstract: Failure behavior of PZT 95/5 under direct current, pulsed electric field and shock compression is studied by experimental and theory analysis in this paper. The electrothermal coupled failure behavior is a key mode when the PZT 95/5 is subjected to direct current. But when the pulsed electric field is applied to the PZT 95/5, the resonance effect and the relation between energy and frequency have been considered, the vibrant energy shifts to high frequency and the possibility of electromechanical-coupled failure behavior is increased with decreasing the pulsed duration. When the pulsed duration is increased, the failure behavior transfers from mechanical coupled with electric failure to direct current mode step by step. The Failure behavior of PZT 95/5 under compression is complex that not only all of failure mechanism in static must be considered but also the microstructure’s evolvement under shock compression should be considered.

Abstract: Electric power of hundreds of kilowatts can be produced in a few microseconds by sudden release of bound charge on the surface of ferroelectric ceramic through shock wave compression. In order to understand the depolarization process, knowledge of the discharge behavior of ferroelectric ceramic under shock wave compression is essential. Gas-gun facility has been used to investigate the shock-induced depolarization kinetics of tin-modified lead zirconate titanate ferroelectric ceramic. Experiments were conducted in the normal mode in which the shock propagation vector was perpendicular to the remanent polarization. Two kinds of specimens with the ferroelectric-toantiferroelectric transformation hydraulic pressure respectively at 80 MPa and 180 MPa were tested. The output currents as a function of load resistance were measured. A computation model was developed to describe the electrical behavior of PSZT ceramic under shock wave compression, which adequately explained the observed experimental results.

Abstract: In the frame of shock-induced depoling, PZT 95/5 ferroelectric ceramics with niobium doped has been assembled for the pulsed power supply, and the electrical current output has been investigated under the action of shock wave in a "normal mode". The electrical response of LRC load especially for the small resistance (R) and small inductance (L) load was studied. Plane-shock-wave tests were conducted, and the PZT 95/5 ceramics stacked in parallel were devised to generate high-power electrical pulse. An output current of 7 kA has been obtained, and the corresponding rise time of the front edge is under 500 ns. Theoretical calculations were conducted and a good agreement with the experiment presented.