【摘要】 采用超重力反应沉淀法制备的纳米钛酸钡粉体和常规陶瓷工艺,通过控制烧结温度在 1200 ~1300℃,分别制备了晶粒尺寸 0.45~2.2μm的致密陶瓷。实验结果表明超重力反应沉淀法制备的粉体具有良好的烧结和介电性能。烧结温度为 1200℃时,相对密度即可达到95%,晶粒尺寸为 0.45μm,随烧结温度的升高,晶粒逐渐长大,未出现晶粒的异常长大现象,到1300℃相对密度和晶粒尺寸分别达到 97.7%和2.2μm。钛酸钡陶瓷介电性能有明显的粒度效应,晶粒在1.2μm左右时,室温介电常数达到最大(4143)。由于晶粒内部立方相成分的出现,包含更细晶粒的陶瓷(d=0.45μm)呈现低的介电常数。更多还原

【Abstract】 Barium titanate （BaTiO₃） powder was prepared by high-gravity reactive precipitation （HGRP） process. BaTiO₃ ceramics with average grain size from 0.45μm to 2.2μm were obtained by the conventional ceramic technology and as-prepared powder. The sintering temperature was adjusted in the range of 1200～1300℃. The experimental results showed that as-prepared BaTiO₃ powder had good sintering and electrical properties. Sintered ceramic can reach the relative density of >95% when sintered at 1200℃; The exaggerated grain growth did not appear when increased the sintering temperature, and the grain size and relative density increased and reached 2.2μm and 97.7% at 1300℃, respectively. The grain size effect on the dielectric constant of the sintered ceramics was also studied. The dielectric constant had a maximum （4143） at 1.2μm grain size. Lower dielectric constant of fine-grains ceramic （d=0.45μm） was attributed to the incomplete development of the tetragonal structure from cubic structure.更多还原