ZnO varistors—Preparation of nano and micro sized powders by mechanical methods for low and high voltage varistors

ZnO-Bi2O3-Sb2O3 varistors are as essential today as they have been since their discovery five decades ago. Their role is to protect other electronic components against oncoming surges of electrons and survive. The demands on varistors are increasing. Electronic components are becoming smaller and more sensitive, and the metal oxides from which varistors are made are precious. Every aspect of their structure (macro, micro, nano and atomic) determines how they perform and survive. Each stage and variable within the powder metallurgy process is important. The mechanical methods in preparing nano and micro sized metal oxide powders are outlined in this chapter.