ZnO压敏陶瓷的PVA系水基流延成型工艺及其性能

Aqueous tape casting of ZnO varistor ceramics with PVA as binder and their properties

采用聚乙烯醇(PVA)系水基流延成型工艺制备了ZnO压敏陶瓷的水基流延膜。用粒度分析、粘度测量和动态机械热分析等方法研究了各组分对水基流延浆料性能的影响,用扫描电子显微镜和X射线衍射仪研究了水基流延膜的微观结构和物相组成。结果表明:在浆料质量比(陶瓷粉体:去离子水:分散剂:粘结剂:增塑剂:表面活性剂)=100:84.6:1:6:5.4:3时,所制水基流延膜无缺陷且微观结构均匀;另外,该流延膜经900℃烧结后具有良好的电性能:电压梯度E1mA=112.4 V/mm,非线性系数=34.6,漏电流密度JL=0.5×10–6A/cm2。

ZnO varistor ceramic tapes were prepared by aqueous tape casting with polyvinyl alcohol as the binder. The effects of components on the properties of the slurry for aqueous tape casting were investigated with particle size analyzer, viscometer and dynamic mechanical analyzer. The microstructure and phase composition of the prepared tapes were studied with environmental scanning electron microscope and X-ray diffractometer. The results show that when the mass ratio of ceramic power to deionized water to dispersant to binder to plasticizer to surfactant is 100 ： 84.6 ： 1 ： 6 ： 5.4 ： 3, the tape shows a homogeneous microstructure with no defect. Moreover, after sintering at 900 ℃, the tape exhibits excellent electrical properties： voltage gradient ElmA = 112.4 V/mm, nonlinear coefficient a= 34.6, leakage current density JL = 0.5×10^-6 A/cm^2.