Research On Preparation Of Porous PZT95/5Ferroelectric Ceramics And The Discharge Characteristic Loaded By Low Speed Compact

Porous ferroelectric ceramics is the new core material of pulse power supplydevices. When loaded by shock wave, the change of its microstructure will affectsthe properties of discharging and breakdown. This is a key problem concerned inthe development and application of practical engineering. In this paper, porousPZT95/5ferroelectric ceramics were prepared using PMMA micro spheres withnonuniform particle size as pore forming agent. And the discharge characteristicsof PZT95/5ferroelectric ceramics loaded by low speed impact stress were studied,using fall-hammer impact testing machine as loading device.The PbO content in composition design was changed to investigate theeffects of Pb content on the structure and properties of PZT95/5ferroelectricceramics. It turns out that PZT95/5ferroelectric ceramics with relative goodferroelectricity and high remnant polarization is acquired when the3%excessPbO is added.PMMA with different particle size distribution were used to research theeffects of pore size distribution on the electrical properties of porous PZT95/5ferroelectric ceramics. The addition of PMMA was changed to study the relationsbetween porosity and the electrical properties of PZT95/5ferroelectric ceramics.The results show that the remnant polarization Pr, permittivity and piezoelectricconstant decrease with the increase of porosity, respectively. While the curietemperature Tc and coercive electric field Ec are not affected. The electricalproperties have not been influenced by the pore size distribution.The effects of impact load on the discharge characteristic of PZT95/5ferroelectric ceramics loaded by low speed impact were studied by changing thedrop hammer height. The effects of fine microstructure on the dischargecharacteristic were studied by using the samples with various porosity and poresize distribution. The resistive load of external circuit was changed to investigatethe influence of external load on the discharge characteristic. The results showthat the change of impact load and fine microstructure of PZT95/5ferroelectricceramics has hardly effect on the discharge characteristic. And the increase of external load has not reduced the current intensity, indicating that the dischargemode of PZT95/5ferroelectric ceramics loaded by low speed impact is theconstant current source model.