Influence of temperature on the electrical characteristic parameters and dynamic electro-mechanical behaviour of PZT-5H

Abstract

In order to study the electromechanical characteristics of PZT-5H in the temperature range of -40~25℃ under the impact loading, the electrostatic parameters of PZT-5H at different temperatures are measured, the liquid nitrogen cooling/Hopkinson mechanical property and piezoelectric ceramic voltage output testing system are built, Hopkinson experiments at different temperatures (-40 ℃ , -25 ℃ , -10 ℃ , 0 ℃ and 25 ℃ ) and different impact velocities are carried out. Experimental results show that , the resistivity and relative permittivity decrease with the temperature of PZT-5H decreasing from 25℃ to -40℃, and the relative permittivity decrease about 27.92%, and the relaxation time is also deduced. By scanning electron microscope (SEM) and Energy Dispersive Spectrometer (EDS) observation, it is found that the blowhole defects and cracks of the piezoelectric ceramics have obvious effects on the electrical output characteristics of piezoelectric ceramics when the piezoelectric ceramics are struck. Based on the analysis of space charge theory, the freezing effect of piezoelectric ceramics caused by the obstruction of domain motion at low temperature is obtained. And the dynamic piezoelectric constant in the elastic region measured is about 1.66 times that of the static piezoelectric constant, which indicates that the relative dielectric constant of the piezoelectric ceramic has changed significantly under dynamic loading.

Analysis of Output Performance of a Novel Symmetrical T-Shaped Trapezoidal Micro Piezoelectric Energy Harvester Using a PZT-5H

“…By reasonably adjusting the structural parameters of the STTM-PEH according to external conditions, a series of harvesters can be obtained and is able to capture ambient vibration with a frequency range of 5-35 Hz, which can provide steady energy for the wireless sensors monitoring the vibrations of mechanical equipment such as machine tools, 3D printers and electric machinery [27]. Firstly, PZT-5H was selected as the piezoelectric material of the STTM-PEH because of its higher brittleness, sensitivity, dielectric constant and electromechanical coupling coefficient than those of PVDF or AlN [28][29][30][31][32]. Subsequently, the finite element model of the T-shaped trapezoidal piezoelectric cantilever beam was established and its modal analysis was performed by COMSOL5.5 (COMSOL Inc, Stockholm, Sweden).…”