Reaction Sintering of ZnO-Al₂O₃
Green, David J. and Halloran, John and Johnson, David W. and Klein, Lisa
The reaction sintering of equimolar mixtures of ZnO and A12O3 powders was investigated as a function of primary processing parameters such as the temperature, heating rate, green density, and particle size. the powder mixtures were prepared by two different methods. in one method, the ZnO and A12O3 powders were ball-milled. in the other method, the ZnO powder was chemically precipitated onto the A12O3 particles dispersed in a solution of zinc chloride. the sintering characteristics of the compacted powders prepared by each method were compared with those for a prereacted, single-phase powder of zinc aluminate, ZnAl2O4. the chemical reaction between ZnO and A12O3 occurred prior to densification of the powder compact and was accompanied by fairly large expansion. the mixing procedure had a significant effect on the densification rate during reaction sintering. the densification rate of the compact formed from the ball-milled powder was strongly inhibited compared to that for the single-phase ZnAl2O4 powder. However, the densification rate of the compact formed from the chemically precipitated mixture was almost identical to that for the ZnAl2O4 powder. the difference in sintering between the ball-milled mixture and the chemically precipitated mixture is interpreted in terms of differences in the microstructural uniformity of the initial powder compacts resulting from the different preparation procedures.
W. Hong et al., "Reaction Sintering of ZnO-Al₂O₃," Journal of the American Ceramic Society, Wiley-Blackwell, Jan 1995.
The definitive version is available at http://dx.doi.org/10.1111/j.1151-2916.1995.tb07957.x
Materials Science and Engineering
Article - Journal
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