Multi-axial non-proportional polarization rotation tests of soft PZT piezoceramics under electric field loading

摘要

In this experimental work, multi-axial, non-proportional polarization rotation tests were performed for a commercial soft PZT material under purely electric field loading. Large pre-poled piezoceramic plates were cut into rectangular blocks of size 15mm x 5mm x 5 mm, with their long axes inclined at a set of angles (from 0° to 180°, in steps of 15°) to the initial poling direction. After cutting, the top and bottom 5mm x 5 mm surfaces were electroded with a thin layer of silver paint and then, a ramp-shaped electric field was applied to cause the polarization to change. In addition to the polarization measurement along the field loading direction, the normal strain responses in all three coordinate directions were monitored simultaneously using strain gauge technique. Based on a series of polarization and strain versus electric field curves, switching (domain reorientation threshold) surfaces were constructed in the bi-axial electric field plane using the conventional offset method. The experimental data can be used to examine the existing switching criteria in phenomenological models for the non-linear constitutive behavior of piezoceramics.