Low-temperture Sintering And Properties Of BCZT-Based Lead-free Piezoelectric Ceramics

Piezoelectric ceramic is a functional material which can realize the function of the conversion between mechanical and electrical power. Lead oxide-based piezoelectric ceramics are still widely used, however, the use of lead-based piezoelectric materials leads to the unstability of the composition because of the high volatilization of lead oxide during the sintering process. Therefore, from the viewpoint of long-term development of the world society, seeking lead-free or low-lead content materials with excellent piezoelectric properties to replace the PZT-based ceramics has become one of the most emergent works.(Ba0.7Ca0.3)Ti03-xBa(Zr0.2Ti0.8)O3has been considered as a good candidate for lead-free piezoelectric ceramics due to its good piezoelectric properties.Fe2O3and CuO are commomnly used for burned agent, rare earth elements Sm2O3can greatly improve the performance of piezoelectric ceramic sintering and get to the electrical properties and stability piezoelectric properties, and other comprehensive properties. A conventional ceramics fabrication technique were used to prepare (Ba0.7Ca0.3)TiO3-Ba(Zr0.2Ti0.8)O3ceramics.The effect of Fe2O3, CuO and Sm2O3on the crystalline structure, the microstructure, the dielectric properties and the piezoelectric properties of BCZT ceramics were also studied. Several important conclusions can be summarized as follows:The relation between composition and crystalline structure, microstructure, piezoelectric properties, dielectric properties of BCZT-xFe system ceramics was systemically investigated. It was found that the addition of Fe2O3significantly improve the sinterability of BCZT ceramics, resulting in a reduction of sintering temperature, meanwhile maintain high piezoelectric properties. SEM images indicate that a small amount of Fe2O3addition affects the microstructure, obviously. Main piezoelectric parameters of these ceramics were optimized around x=0.04wt%with d33=400pC/N, kp=0.43, Qm=51, tanδ=2.3%, εr=3482.The relation between composition and crystalline structure, microstructure, piezoelectric properties, dielectric properties of BCZT-xCu system ceramics was systemically investigated. It was found that the addition of CuO significantly improve the sinterability of BCZT ceramics, resulting in a reduction of sintering temperature from1540℃to1350℃, meanwhile maintain high piezoelectric properties. SEM images indicate that a small amount of CuO addition affects the microstructure, obviously. Main piezoelectric parameters of these ceramics were optimized around x=0.04wt%with d33=510pC/N, kp=41%, Qm=19, tanδ=1.25%, εr=3762.The relation between composition and crystalline structure, microstructure, piezoelectric properties, dielectric properties of BCZT-xSm system ceramics was systemically investigated. It was found that the addition of Sm2O3significantly improve the sinterability of BCZT ceramics, resulting in a reduction of sintering temperature from1540℃to1350℃, meanwhile maintain high piezoelectric properties. SEM images indicate that a small amount of Sm2O3addition affects the micro structure, obviously. Main piezoelectric parameters of these ceramics were optimized around x=0.04wt%with d33=590pC/N, kp=0.52, Qm=43, tanδ=1.3%, εr=3372. The results indicate that the BCZT-xSm ceramics are promising lead-free practical applications.The effect of Fe2O3, CuO and Sm2O3on the crystalline structure, the micrograph and the electrical properties of BCZT system ceramics was analyzed systemically. Though the phase structure of BCZT-xFe、BCZT-xCu、BCZT-xSm systems are all typical perovskite compound, the influence of Fe2O3, CuO and Sm2O3addition is quite different. Rare earth elements Sm2O3can improves the comprehensive performance of BCZT more significantly.