Pore–Boundary Separation Behavior during Sintering of Pure and Bi2O3-Doped ZnO Ceramics |
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| Authors: | Jung-Hae Choi Nong-Moon Hwang Doh-Yeon Kim |
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| Affiliation: | Center for Microstructure Science of Materials and School of Materials Science and Engineering, Seoul National University, Seoul 151-742, Korea, and Daedok 305-600, Korea;Korea Research Institute of Standards and Science, c |
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| Abstract: | Pore–boundary separation in ZnO and 99.95ZnO·0.05Bi2O3 (in mol%) specimens during sintering at 1200°C was investigated. In pure ZnO specimens, pores were attached to the grain boundaries and disappeared during the final stage of sintering. In the Bi2O3-doped specimens, on the other hand, many pores were separated from the boundaries and trapped inside the grains. Observation using transmission electron microscopy showed that a thin layer of Bi2O3-rich phase existed at the boundaries in the Bi2O3-doped specimens. The pore separation in 99.95ZnO·0.05Bi2O3 specimens was explained in terms of the dihedral angle change and the high mobility of a liquid film boundary. |
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| Keywords: | zinc oxide varistors sinter/sintering additives |
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