HONG Yan 1, XIE Jun 2, WANG Zhumei 3, SHEN Zongyang 4, XIE Zhixiang 5, LI Yueming 6
(Jiangxi Key Laboratory of Advanced Ceramic Materials, School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, Chin)
Abstract:In this paper, K0.5Na0.5 NbO3 (KNN) synthesized by solid state reaction as base materials, flake Sr2Bi4Ti5O18 grain prepared by molten salt synthesis method as template, the KNN textured lead-free piezoelectric ceramic was prepared by aqueous tape-casting technique, and the effect of sintering temperature on the performance was studied. The results showed that the sintering temperature has very important influence on the linear shrinkage, bulk density, texturing and piezoelectric properties. With the increase of sintering temperature, the performance increases and reaches maximum at 1120 ℃ and then decreases. In the parallel tape-casting direction, the piezoelectric constant d33 reaches 113 pC/N, the planar electromechanical coupling coefficient kP is 39.4%, the dielectric constant εT 33/ε0 is 486; and at the perpendicular direction, the d33 is only 82 pC/N, the kP is 35.5%, and the εT 33/ε0 is 456, showing obvious anisotropy.
Key words:potassium-sodium niobate; Sr2Bi4Ti5O18, texturing; lead-free piezoelectric ceramic; aqueous tape-casting