(1-x)KNN-xCT无铅压电陶瓷的制备及性能研究

In this paper, lead-free piezoelectric ceramics with high piezoelectric constant, high electromechanical coupling factor, high Curie temperature and low dielectric loss are the focuses of the modern research. The alkaline niobate-based lead-free piezoelectric ceramics have drawn greater attention because of their superior property. A series of CaTiO3 doped (K0.5Na0.5)NbO3 (KNN) lead-free piezoelectric ceramics were prepared by normal solid-phase synthesis method The results show that the KNN-CT ceramics own a perovskite structure and a morphotropic phase boundary was found when x is around 4%. The maximum density of the ceramics has reached to 99% of the theoretical density. Both of piezoelectric constant and electromechanical coupling factor reach to their maximal: d33=94pC/N, Kp=33.2%. The text of ferroelectric properties show that KNN-CT ceramics have typial P-E hysteresis loops, Pr=10.7μC/cm2，Ec=1740V/mm Compared with the pure piezoelectric ceramics, TO-T and Tc of KNN-CT is lower, while the dielectric constant increased sharply.