Bi_(1/2)Na_(1/2)TiO_3-BaTiO_3系无铅压电陶瓷制备工艺的优化及其结构分析

Optimization of the process for Bi_(1/2)Na_(1/2)TiO_3-BaTiO_3 ceramics and discussion on the microstructure

借助正交试验设计，通过对无铅压电陶瓷压电、介电性能的测试，研究了BaTiO3含量、预烧温度、烧结温度及保温时间对（1-x）（Bi1／2Na1／2）TiO3-xBaTiO3（简写为BNBT-100x）陶瓷性能的影响。研究结果表明制备BNBT系陶瓷的最优化工艺条件为：BaTiO3摩尔分数x=0．06、预烧温度850℃、烧结温度1130℃、保温时间2h。通过XRD分析了BNBT系压电陶瓷的晶体结构类型、晶胞参数及晶格畸变随着BaTiO3摩尔分数的变化，确定了该体系的三方-四方的准同型相界在x=0．06～0.08之间。

The effects of the process parameters such as BaTiO3 content, calcining temperature, sintering temperature and soaking time on the properties of the （ 1 - x） （ Bi1/2Na1/2 ） TiO3-xBaTiO3 （BNBT-100x） lead free piezoelectric ceramics are investigated using the orthogonal design. And the results show that the optimal conditions of preparing BNBT ceramics are： BaTiO3 content 0. 06, calcining temperature 850 ℃, sintering temperature 1 130 ℃ and soaking time 2 h. The variations of the crystal structure, lattice parameters and lattice distortion with the BaTiO3 contents of the BNBT piezoelectric ceramics were also studied. It was found out that the rhombohedral-tetragonal MPB would lie in the composition range when x = 0. 06 -0. 08 by XRD analysis.