Influence of cyclical electric load on crack growth in piezoelectric ceramics under a constant mechanical load

Piezoelectric material has widely used in various applications with its high liable performance and quite smart electro-mechanical characteristics. However, solutions for number of troubles in strength and behavior of fracture have not sufficiently clarified yet. Among these associated solutions, the double torsion (DT) technique is the particular and effective method to measure toughness of fracture and growth behavior of slow crack in ceramic material. From the results of this work, it obtained the practical feasibility of the DT technique for finding growth behavior of crack initiated by kinds of cyclic electric fatigue on piezoelectric ceramics, and found that the initiated crack is able to propagate by using a relatively lower cyclical voltage than before cases under a constant mechanical load if the DT technique is used. In this study, it is also established the experimental method of the crack propagation by cyclic electric fatigue for the piezoelectric ceramics using DT technique, and found the possibility of the power law based on the classical Paris’ equation for analyzing the result of electric fatigue crack test.