Role of Al2O3 in Sintering of Submicron Yttria-Stabilized ZrO2 Powders.
Technical rept. no. 8 (Final) Oct 80-30 Sep 83,
ILLINOIS UNIV AT URBANA DEPT OF CERAMIC ENGINEERING
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The use of A12O3 up to approximately 3.5 wt as a sintering aid to promote rapid densification of precipitated yttria 8.0 wt. stabilized Zirconia YSZ powders in the range 1100 - 1350 C, was investigated. The A12O3 was added as hydrated A1OH and dispersed by milling in a 60 40 alcohol water solution, followed by pressing at 205 MPa. Significantly increased densification was obtained with A12O3, even below 1200 C, and optimum densification 99.0 Th.D. occured at 1350 C1 hr. with 0.325 wt A12O3. These samples exhibited enhanced electrical conductivity and larger grain size 0.3 - 0.5 micrometer. TEM microstructural observations and densification kinetic data indicated a liquid phase assisted sintering mechanism. Solid state doping of the ZrO2 by A1 was inferred from the electrical conductivity data.
- Metallurgy and Metallography
- Fabrication Metallurgy