TY - JOUR
T1 - Isothermal sintering effects on phase separation and grain growth in yttria-stabilized tetragonal zirconia polycrystal
AU - Matsui, Koji
AU - Yoshida, Hidehiro
AU - Ikuhara, Yuichi
PY - 2009/2/1
Y1 - 2009/2/1
N2 - The isothermal sintering behavior in 3 mol% yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) was investigated to clarify phase-separation and grain-growth mechanisms during sintering. In the Y-TZP sintered at 1300°C for 2 h, the Y3+ ion distribution of grain interiors in Y-TZP was nearly homogeneous, but Y3+ ions segregated along grain boundaries within a width of about 10 nm. When the holding time increased from 2 to 50 h, the cubic-phase regions with high Y3+ ion concentrations were clearly formed in the grain interiors adjacent to the grain boundaries, though the average grain size hardly increased. This result shows that the cubic-phase regions were formed without grain growth, which can be explained by the grain-boundary segregation-induced phase transformation mechanism. In the Y-TZP sintered at 1500°C for 2 h, the cubic-phase regions were already formed, and both of the cubic-phase region and average grain size increased with increasing holding time. This grain-growth behavior can be interpreted by the third-power growth low derived based on the solute drag theory, which indicates that the cubic-phase regions do not effectively act as the pinning points.
AB - The isothermal sintering behavior in 3 mol% yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) was investigated to clarify phase-separation and grain-growth mechanisms during sintering. In the Y-TZP sintered at 1300°C for 2 h, the Y3+ ion distribution of grain interiors in Y-TZP was nearly homogeneous, but Y3+ ions segregated along grain boundaries within a width of about 10 nm. When the holding time increased from 2 to 50 h, the cubic-phase regions with high Y3+ ion concentrations were clearly formed in the grain interiors adjacent to the grain boundaries, though the average grain size hardly increased. This result shows that the cubic-phase regions were formed without grain growth, which can be explained by the grain-boundary segregation-induced phase transformation mechanism. In the Y-TZP sintered at 1500°C for 2 h, the cubic-phase regions were already formed, and both of the cubic-phase region and average grain size increased with increasing holding time. This grain-growth behavior can be interpreted by the third-power growth low derived based on the solute drag theory, which indicates that the cubic-phase regions do not effectively act as the pinning points.
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U2 - 10.1111/j.1551-2916.2008.02861.x
DO - 10.1111/j.1551-2916.2008.02861.x
M3 - Article
AN - SCOPUS:60849089331
VL - 92
SP - 467
EP - 475
JO - Journal of the American Ceramic Society
JF - Journal of the American Ceramic Society
SN - 0002-7820
IS - 2
ER -