Electrical degradation process and mechanical performance of piezoelectric ceramics for different poling conditions

The mechanical and electrical properties of piezoelectric ceramics have been investigated, with special emphasis on the effects of poling conditions. The materials used in the study are the commercial piezoelectric ceramics PbZrO₃-PbTiO₃ (PZT) and BaTiO₃. With regard to the effect of the voltage values applied in poling on the piezoelectric constant and mechanical fatigue properties, it was found that fatigue resistance increases with increasing applied voltage. The electrical degradation process and the mechanical performance of the PZT samples appear to be most favorable when the poling of samples is performed under the condition of repoling via aging treatment after poling. The application of a DC field at a temperature above the Curie point to the BaTiO₃ samples before ordinary poling is very effective for the improvement of electrical and mechanical properties. It was found that such a prior treatment in poling increases the piezoelectric coupling constant of the samples. Prior treatment could also effectively work to suppress the degradation of piezoelectric properties under fatigue loading and to improve the mechanical strength properties