Effect of Crystal Shape on the Grain Growth during Liquid Phase Sintering of Ceramics |
Wook Jo, Nong-Moon Hwang1, Doh-Yeon Kim |
Department of Materials Science and Engineering, Seoul National University 1National Research Laboratory of Charged Nanoparticles, Seoul National University |
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ABSTRACT |
The equilibrium or growth shape of ceramic materials is classified largely into two categories according to the thermodynamic conditions imposed. One is a polyhedral shape where the surface free energy is anisotropic, and the other a spherical shape where the surface free energy is isotropic. In the case of grains with a polyhedral shape of anisotropic surface free energy, socalled abnormal grain growth usually takes place due to a significant energy barrier for a growth unit to be attached to the crystal surface. In the case of grains with a spherical shape of isotropic surface free energy, however, normal grain growth with a uniform size distribution takes place. In this contribution, the state-of-the-art of our current understanding of the relationship between the crystal shape and the microstructure evolution during the sintering of ceramic materials in the presence of a liquid phase was discussed. |
Key words:
Liquid phase sintering, Grain growth, Crystal shape, Surface free energy, Interface structure |
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