冷冻成型工艺制备层状多孔氧化铌陶瓷

以氧化铌(Nb2O5)为起始原料,聚丙烯酸作分散剂,利用冷冻成型工艺制备了具有层状孔道结构的多孔氧化铌陶瓷。研究了浆料固相含量和烧结温度对产物形貌、物相结构和孔径尺寸大小及分布的影响规律。实验结果表明,多孔氧化铌陶瓷的孔道复制了冰模板的形貌,形成了均匀的层状孔道结构,孔隙率的大小随浆料固相含量的增加而减小;在相同固含量下,烧成温度越高,材料孔径从双峰分布变为单峰分布,开孔隙率下降。在1400℃烧结得到α-Nb2O5纤维状颗粒组成的多孔氧化铌陶瓷。

Porous Nb2O5 ceramics with laminated structure fabricated by freeze casting

Highly aligned laminated structures of porous niobium oxide have been fabricated using ice-based freeze-casting techniques. The different parameters of the process,such as the solids content of the suspension,the sintered temperature have been studied to determine their influence on the microstructure,density and distribution of pores of the sintered samples.The pore structure was substantially affected by the starting slurry concentration and sintering temperature.A porous niobium oxide with high porosity (50 %~70 %)was obtained and its porosity somewhat decreased when the slurry concentration increased.The porous Nb2O5 ceramics sintering at 1 400 ℃ had a unique microstructure, where macroscopically aligned open pores contained fibrousα-Nb2O5 grains protruding from the internal walls of the Nb2O5 matrix.