与Ag内电极共烧对ZnVSb压敏陶瓷显微结构及性能的影响

Effects of Co-firing with Ag Inner-electrode on Microstructure and Properties of ZnVSb Varistor Ceramics

研究共烧影响及其机理是开发多层片式压敏电阻的基础和关键。采用XRD、SEM、EDS研究了与Ag内电极共烧对ZnVSb陶瓷显微形貌、晶体结构及烧结性能的影响。结果表明,与Ag内电极共烧不影响ZnVSb陶瓷的相组成,但阻碍ZnVSb陶瓷烧结。Ag通过富V液相扩散并恶化其与ZnO晶粒的浸润性,从而阻碍ZnVSb陶瓷的致密化进程。Zn在Ag内电极中不存在扩散,而Sb在其中的扩散破坏了ZnVSb陶瓷原有的成分配比。研究结果为ZnVSb基片式压敏电阻开发奠定了基础。

Effects of co-firing on the performance of varistor ceramics and its mechanism is one of key factors for multilayer chip varistors.The effects of co-firing with pure Ag electrode on the phase constituent and microstructure of ZnVSb varistor ceramics were studied by means of X-ray diffractometry（XRD）,scanning electron microscopy（SEM） and X-ray energy-dispersive spectroscopy（EDS）.The results show that co-firing with Ag inner electrode has no observed effect on the phase constituents of ZnVSb based varistor ceramics.During the sintering process,Ag diffuses through the V rich phase,and then deteriorates the wetting of vanadium rich phase on ZnO grains.Consequently,the densification of ZnVSb ceramics is inhibited.In contrast to Sb,Zn has no diffusion within Ag inner electrode.The diffusion of Sb changes the original optimized composition of ZnVSb varistor ceramics.The results provide the foundation for the future development of ZnVSb based chip varistors.