Reaction sintering of ZnO-Al{sub 2}O{sub 3}

Journal Article · Fri Dec 01 04:00:00 EST 1995 · Journal of the American Ceramic Society

DOI:https://doi.org/10.1111/j.1151-2916.1995.tb07957.x· OSTI ID:177975

Hong, W S; Jonghe, L.C. De ^[1]; Yang, X; Rahaman, M N ^[2]

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1. Lawrence Berkeley Lab., CA (United States). Materials Sciences Div.
2. Univ. of Missouri, Rolla, MO (United States). Dept. of Ceramic Engineering

The reaction sintering of equimolar mixtures of ZnO and Al{sub 2}O{sub 3} 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 Al{sub 2}O{sub 3} powders were ball-milled. In the other method, the ZnO powder was chemically precipitated onto the Al{sub 2}O{sub 3} 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 pre-reacted single-phase powder of zinc aluminate, ZnAl{sub 2}O{sub 4}. The chemical reaction between ZnO and Al{sub 2}O{sub 3} 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 ZnAl{sub 2}O{sub 4} powder. However, the densification rate of the compact formed from the chemically precipitated mixture was almost identical to that for the ZnAl{sub 2}O{sub 4} powder. The difference in sintering between the ball-milled mixture and the chemically precipitated mixture is interpreted in terms of differences i the microstructural uniformity of the initial powder compacts resulting from the different preparation procedures.

• Sponsoring Organization: USDOE
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 177975
• Journal Information: Journal of the American Ceramic Society, Journal Name: Journal of the American Ceramic Society Journal Issue: 12 Vol. 78; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM OXIDES
BULK DENSITY
CHEMICAL REACTIONS
DIFFUSION
HEATING RATE
MILLING
PARTICLE SIZE
POWDERS
PRECIPITATION
SINTERING
SPINELS
TEMPERATURE DEPENDENCE
ZINC CHLORIDES
ZINC OXIDES