烧结温度对BaTiO3多孔陶瓷性能的影响

采用水基冷冻浇注法制备了具有层状结构的BaTiO3多孔陶瓷,研究了烧结温度对多孔陶瓷微观形貌、收缩率、孔隙率及介电性能的影响,并探讨了高岭土悬浮剂在烧结过程中所起的作用.研究结果表明:高岭土含量4wt%的样品收缩率从1 200℃时的27%升高到1 220℃时的56%,同时孔隙率从78%下降到56%,高岭土含量8wt%的样品收缩率从1 200℃时的30%升高到1 220℃时的61%,同时孔隙率从72%下降到39%;高岭土在烧结过程中起到烧结助剂的作用;烧结温度升高会使孔径变小并导致孔隙排列由有序结构向无序结构转变.高岭土含量为8wt%,烧结温度1 200℃时,可以得到分布均匀的层状结构多孔陶瓷;高岭土含量为4wt%,烧结温度1 220℃时可得到介电常数130的多孔陶瓷.

Effect of sintering temperature on the properties of porous BaTiO3 ceramics

BaTiO3 porous ceramics with layered structure were prepared by water based freeze casting technology. The effect of sintering temperature on the microstructure, shrinkage, porosity and dielectric properties of porous BaTiO3 was investigated and effect of kaolinite on sintering process was discussed. The results show that the shrinkage of sample with 4 wt% kaolinite content increased from 27% to 56% when temperature increased from 1 200 ℃ to 1 220 ℃, then porosity decreased from 78% to 56~. The shrinkage of sample with 8 wt% kaolinite content increased from 30% to 61%when temperature increased from 1 200 ℃ to 1 220 ℃, then porosity decreased from 72% to 39%. Kaolinite could decrease sintering tem- perature of porous ceramics. The pore size decreased and pore arrangement transformed from ordered structure to disordered structure with increase of sintering temperature. Porous ce- ramics with 8 wt% kaolinite content would obtain layered structure when sintering at 1 200 ℃. The dielectric constant of sample was 130 when kaolinite addition was 4 wt%and sinte- ring at 1 220 ℃.