流延成型法制备三氧化二铝陶瓷膜基体(Ⅱ)——陶瓷膜基体的性能及结构表征

A Study on Processing of Alumina Ceramic Membranes Substrate by Tape Casting(Ⅱ):Characterization of Ceramic Membranes Substrate

以苯丙乳胶液为粘接剂,水为分散介质,采用流延成型法制备了氧化铝陶瓷膜生坯体。通过对生坯体烧结后气孔率及断裂强度的测定,讨论了烧结温度及粘接剂含量对气孔率和断裂强度的影响。结果表明,随烧结温度的升高,基体的断裂强度增加,而气孔率有降低的趋势。在同一烧结温度下,随着粘结剂含量的增加,基体的气孔率增加,在添加了增稠剂羟乙基纤维素(HEC)后,气孔率进一步增加,但增加量不大,并且导致浆体粘度增加,不易流延成型。通过对不同烧结温度的基体的扫描电镜观察发现,氧化铝粒子分布比较均匀,随着温度的升高,晶粒明显长大,致密性提高,气孔率下降。

The preparation method of ceramic membrane substrate by tape casting technique using aqueous slurries containing latex binder was studied. The results showed that the fracture strength increased and porosity of substrates decreased respectively with the sintering temperature increasing. At the same sintering temperature, the porosity of the substrate increased as the content of latex binders increased. After the hydroxyethylcellulose was added, the porosity increased slightly. However, the viscosity of slurries increased and tape casting is difficult because of the addition of cellulose binder. The microstructures of substrates sintered at different temperatures were studied by SEM. The results showed the homogenous distribution of alumina particles and obvious growth of crystals. Therefore the density of substrate increased, leading to an increased fracture strength and decreased porosity.