Research on Mechanism of Improving Electrical Properties of ZnO Varistor Ceramics by Laser Shock Processing

Abstract:

In order to improve electrical properties, annealed ZnO varistor ceramics have been treated by laser shock processing (LSP). Electrical parameters of the annealed ZnO varistor ceramics were measured by CJ1001 Varistor Tester. Morphology and microstructure of the annealed ZnO varistor ceramics were gained by XRD and SEM. The results indicate that compared with the electrical properties of the annealed ZnO varistor ceramics, the voltage gradient of the ZnO varistor ceramics treated by LSP remains the same, the nonlinear coefficient substantially increases by 31.6%, and the leakage current reduces by 33.3%. Meanwhile, the phase composition of the annealed ZnO varistor ceramics is mainly composed of ZnO main phase, Zn_2.33Sb_0.67O₄, β-Bi2O3, and δ-Bi₂O₃ phase; while the phase composition of the ZnO varistor ceramics remains the above four phases in the compound state (anneal and then LSP), but the content of δ-Bi₂O₃ phase increases. The increase of δ-Bi₂O₃ phase content is the main reason for improving the electrical properties of the annealed ZnO varistor ceramics.

• Periodical: Applied Mechanics and Materials (Volumes 37-38)
• Pages: 1045-1049
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.37-38.1045
• Online since: November 2010
• Authors: Rui Fang Chen, Yin Qun Hua, Guang Ji, Zhen Zhen Sun
• Keywords: Electrical Properties, Laser Shock Wave, Phase Transition

References

[1] T.K. Gupta: Journal of the American Ceramic Society, Vol. 73 (1990), pp.1817-1840.

[2] M. Tsuoka: Japanese Journal of Applied Physics, Vol. 10 (1971), pp.736-746.

[3] L. Fang, Z. Xu and Z.Y. Cheng: Jiangsu Ceramics, Vol. 35 (2002), pp.33-35(in Chinese).

[4] I. Atsushi, M. Michio and M. Takeshi: Japanese Journal of Applied physics, Vol. 15 (1976), pp.1847-1848.

[5] J.H. Jang, H.S. Kim, D.P. Norton and V. Craciun: Journal of Crystal Growth., Vol. 311 (2009), pp.3143-3146.

[6] M.X. Shi and X.M. Wen: Applied Laser, Vol. 20(2000), pp.35-37.

[7] Z.Y. Xu: Martensie Transformation and Martensite (China Science Press, China 1999). (in Chinese).

[8] T.K. Gupta and W.G. Carlson: Journal of Materials Science, Vol. 20(1985), pp.3487-3500.

[9] H.Y. Liu: Preparation and Study on Microstructure and Electrical Properties of ZnO-based Varistor Ceramics with High Voltage-gradient, (East China University doctoral dissertation, China 2006 ). (In Chinese).

[10] Z.L. Wang and S.T. Li: Manufacture and Application of Zinc Oxide Varistors (China Science Press, China 2009) (In Chinese).

[11] D. H. Tang, Y. Zhuang, L. Li and Z.X. Chen: J. Huazhong Univ. of Sci. & Tech, (Nature Science Edition). Vol. 30(2002), pp.46-49 (in Chinese).