Performance and Mechanism Research on ZnO Varistor Ceramics Prepared by Microwave Sintering

To solve the problems of high sintering temperature, uneven grain growth, and limited electrical property optimization in traditional ZnO varistor ceramics, this study adopted microwave sintering (1000°C–1100°C, ZnO matrix with Bi 2 O 3 dopants), using conventional sintering as a reference. Results showed that microwave sintering shortened the cycle and inhibited abnormal grain growth, achieving optimal performance at 1100°C/30 min (potential gradient: 340.82 V/mm, leakage current: 2.16 µA/cm 2 , nonlinear coefficient: 55.09). Mechanisms were revealed via XRD, SEM, and electrical property tests, providing technical and theoretical support for efficient preparation and performance optimization of ZnO varistor ceramics.