Articles
  • High surge energy capability and deterioration stability in ZnO varistors: role of sintering and post-heat-treatment conditions

  • Yu-min Kima, Sung-man Kanga, Sunshin Junga, Kyoung-joo Leea, Ji-hye Kwaka and Seung-kyu Choia,*

  • aElectrical Environment Research Center, Korea Electrotechnology Research Institute, Changwon 51543, Republic of Korea

  • This article is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

This study investigates a ZnO varistor exhibiting both high energy-handling capability and exceptional stability under high-temperature conditions. The results indicate that the sintering temperature and subsequent post-heat-treatment significantly affect the varistor's energy capacity and resistance to degradation. A systematic investigation of the microstructural and phase transformations induced by varying thermal processing conditions revealed that specimens sintered at 1200 °C and post-annealed at 600–800 °C achieved optimal performance, primarily due to grain boundary stabilization and the formation of beneficial intergranular phases.


Keywords: ZnO varistor, Post-annealing, Bismuth oxide, Energy capability, Electrical degradation.

This Article

  • 2025; 26(3): 507-511

    Published on Jun 30, 2025

  • 10.36410/jcpr.2025.26.3.507
  • Received on May 1, 2025
  • Revised on Jun 10, 2025
  • Accepted on Jun 11, 2025

Correspondence to

  • Seung-kyu Choi

  • Electrical Environment Research Center, Korea Electrotechnology Research Institute, Changwon 51543, Republic of Korea
    Tel : +82 552802440 Fax: +82 552801329

  • E-mail: keri87@keri.re.kr