Piezoelectric Properties of Modified (K0.5Na0.5)NbO3-BaTiO3 Ceramics with the Mixture Sintering Aids of 0.6B2O3-0.4CuO

A combined sintering aid mixture of B2O3 and CuO for lead-free piezoelectric ceramics 0.95K(0.5)Na(0.5)NbO(3)-0.05BaTiO(3) (KNN-BT) is introduced. The effects of the mixture sintering aids of 0.6B(2)O(3)-0.4CuO on the sintering behavior, microstructure, and electrical properties for KNN-BT are investigated. Adding 2wt% of sintering aids can effectively broaden the narrow range of sintering temperature from 20 degrees C to above 50 degrees C and enlarge the grain of samples as well as hold the high density of sample sintered at low temperature. The increase of gain size contributed to the improvement in electrical properties. High piezoelectric properties with d(33) = 205pC/N, k(p) = 38.0%, epsilon(33) (T)/epsilon(0) = 1254, and tan delta = 0.026 are obtained for sample of KNN-BT-ywt%(B2O3-CuO) with y = 2 sintered at 1120 degrees C.