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Sintering Kinetics at Isothermal Shrinkage: Effect of Specific Surface Area on the Initial Sintering Stage of Fine Zirconia Powder
Author(s) -
Matsui Koji,
Matsumoto Akira,
Uehara Masato,
Enomoto Naoya,
Hojo Junichi
Publication year - 2007
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2006.01341.x
Subject(s) - sintering , shrinkage , materials science , isothermal process , activation energy , cubic zirconia , diffusion , specific surface area , surface diffusion , composite material , thermodynamics , ceramic , chemistry , adsorption , biochemistry , physics , catalysis
The isothermal shrinkage behaviors of fine zirconia powders (containing 2.8–2.9 mol% Y 2 O 3 ) with specific surface areas of about 6 and 16 m 2 /g were investigated to clarify the effect of specific surface area on the initial sintering stage. The shrinkage of powder compact was measured under constant temperatures in the range of 1000°–1100°C. The increase in specific surface area enhanced the densification rate with increasing temperature. The values of activation energy ( Q ) and frequency‐factor term (β 0 ) of diffusion at initial sintering were estimated by applying the sintering‐rate equation to the isothermal shrinkage data. The Q of diffusion changes little but the β 0 increases with the increase in specific surface area. It is therefore concluded that the increase in the specific surface area of fine zirconia powder enhances the shrinkage rate because of an increase in the β 0 at the initial stage of sintering.