Preparation of 0.84(K0.48Na0.52)NbO3-0.16K0.56Li0.38NbO2.97 Lead-free Piezoelectric Ceramics by Multi-layer Process

0.84(K0.48Na0.52)NbO2.97-0.16K(0.56)Li(0.38)NbO(2.97) lead-free piezoelectric ceramics were prepared by multi-layer process. Effects of sintering temperature and holding time on the density, crystal structure, microstructure, dielectric, and piezoelectric properties of the ceramics were investigated. All the ceramics exhibit a coexistence of perovskite and tungsten bronze structure. The ceramics sintered at 1050 degrees C for 8 min exhibit the largest relative density up to 95%, and the optimized dielectric constant, dielectric loss, and piezoelectric constant of epsilon(r)=618, tan delta=0.03, and d(33)=112 pC/N, respectively. Moreover, the volatilization of K and Na is inhibited due to the lower sintering temperature and much shorter holding time of the multi-layer process.