Abstract:
ZnO based varistors are today used for making state of the art surge arresters for all voltage levels. Essentially they are “n” semi-conductor ceramics made of ZnO (more than 90% molar percents) and many other oxides having different structural roles. This paper presents a new manufacturing technology based on 2 additional oxides Cr2O3 and MnO2, compared with the old one, having five oxides (Cr2O3, MnO2, Co3O4, Bi2O3, NiO). This varistor material has a smaller electrical capacity, suitable for telecommunication applications. The chemical compositions of this new material as well as all the phases of the manufacturing process are presented too.
Keywords:
manufacturing process, five and two additives, metal oxides varistors
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