TY - JOUR
T1 - Sintering mechanism of fine zirconia powders with alumina added by powder mixing and chemical processes
AU - Matsui, Koji
AU - Yamakawa, Takanori
AU - Uehara, Masato
AU - Enomoto, Naoya
AU - Hojo, Junichi
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2008/4
Y1 - 2008/4
N2 - The present study examined the sintering behavior of fine zirconia powders (containing 2.9 mol% Y2O3) with and without small amounts of Al2O3 added by different ways: powder mixing (PM), homogeneous precipitation (HP), and hydrolysis of alkoxide (HA). The initial sintering behavior was examined by both measurement methods of a constant rate of heating and isothermal shrinkage. In the PM process, Al2O 3 particles pinned the shrinkage of zirconia powder compact at the initial stage and diffuse toward zirconia surface to enhance the sintering. This initial sintering mechanism was explained by the grain-boundary diffusion for the Al2O3-free powder and the volume diffusion for Al 2O3-added powder. When Al2O3 was added to zirconia powder by HP and HA processes, the densification rate was more stimulated compared to the PM process. The initial sintering mechanism did not change by the way for Al2O3 addition. The Al 2O3 addition by chemical processes of HP and HA tended to enhance the grain growth of zirconia, while the uniform microstructure was achieved because of homogeneous addition of Al2O3 by those processes.
AB - The present study examined the sintering behavior of fine zirconia powders (containing 2.9 mol% Y2O3) with and without small amounts of Al2O3 added by different ways: powder mixing (PM), homogeneous precipitation (HP), and hydrolysis of alkoxide (HA). The initial sintering behavior was examined by both measurement methods of a constant rate of heating and isothermal shrinkage. In the PM process, Al2O 3 particles pinned the shrinkage of zirconia powder compact at the initial stage and diffuse toward zirconia surface to enhance the sintering. This initial sintering mechanism was explained by the grain-boundary diffusion for the Al2O3-free powder and the volume diffusion for Al 2O3-added powder. When Al2O3 was added to zirconia powder by HP and HA processes, the densification rate was more stimulated compared to the PM process. The initial sintering mechanism did not change by the way for Al2O3 addition. The Al 2O3 addition by chemical processes of HP and HA tended to enhance the grain growth of zirconia, while the uniform microstructure was achieved because of homogeneous addition of Al2O3 by those processes.
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U2 - 10.1007/s10853-008-2493-5
DO - 10.1007/s10853-008-2493-5
M3 - Article
AN - SCOPUS:43249131146
VL - 43
SP - 2745
EP - 2753
JO - Journal of Materials Science
JF - Journal of Materials Science
SN - 0022-2461
IS - 8
ER -