The Difference of High-Temperature Sintering Between Surface-Coated and Mechanically Mixed ZnO Composite Powders
摘要
ZnO varistors prepared by surface coating technology show certain potential in reducing grain size, refining microstructure, and improving electrical properties. The sintering process after powder preparation also has a decisive influence on the performance of the varistor. In this study, based on the simplest binary formulation of ZnO, the common additives SiO2 and Bi2O3 were selected to form ZS and ZB binary system. The surface-coated composite powder and mechanically mixed composite powder were prepared in two kinds of system. The differences of coated powder and mixed powder in sintering process at high temperature were compared from three aspects: powder morphology, thermal analysis, and phase analysis. The results can provide a reference for the sintering process optimization of ZnO coated powder.