Investigation of Partial Discharge and Fracture Strength in Piezoelectric Ceramics

摘要

Although piezoelectric ceramics are widely used, the structural reliability of these materials in long-term service is still a concern. In this study, a nondestructive method for assessing material strength reliability using partial discharge (PD) tests is proposed. The PD inception electric field and the flexure strength are both controlled by the defects in the ceramics which suggests that the PD test can be an alternative nondestructive method for evaluating the structural reliability of piezoelectric ceramics. PD and four-point flexure tests were carried out on piezoelectric ceramics. The influence of the PD test on samples was investigated by comparing the microstruc-ture and electrical properties before and after the PD test. Samples which were not PD tested were also fractured and compared. It was found that no strength degradation was caused by the PD test. Weibull analysis revealed a correlation between the distribution in values for PD inception electric field and flexure strength.