Product Code: PIC2008_P110

Laser Sintering of (K0.5Na0.5Nbo3)-Litao3 Lead-free Ceramics with Novel Piezoelectric Properties
Authors:
Lingfei Ji, Institute of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Xinyu Du, Institute of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Yijian Jiang, Institute of Laser Engineering, Beijing University of Technology; Beijing Peoples Republic of China
Presented at PICALO 2008

High dense and textured structure are the two important factors to improve the piezoelectric properties of K0.5Na0.5NbO3 (KNN)-based ceramics, a promising lead-free piezoelectric ceramics because of their environment-friendly properties.
In this paper, by CO2 laser sintering technique, high dense textured KNN-LiTaO3 ceramics with 92% theoretical density were prepared. The dielectric, piezoelectric and electromechanical properties were found to be ε ~ 510, d33 ~ 120 pC/N, and kp ~ 36.6%, while with high Curie temperature of about 420 °C and low dielectric loss of about 0.03~0.04. The sintering time takes about 20 minutes, which is much shorter than that of traditional sintering usually of several or decade hours. The suppression of O2 discharged by the coaxial gas injection systems on the volatilization of the K+, Na+ and Li+ during laser heating leads to the successful preparation of high dense ceramic. The enhanced Curie temperature associated with the high temperature phase transition induced by the instant adjustment of laser power density from 0.07 kW/cm2 to 0.28 kW/cm2 just during 2~5 s.