Interdependence between green compact property and powder agglomeration and their relation to the sintering behaviour of zirconia powder

Citation
Dm. Liu et al., Interdependence between green compact property and powder agglomeration and their relation to the sintering behaviour of zirconia powder, CERAM INT, 25(6), 1999, pp. 551-559
Citations number
23
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science","Material Science & Engineering
Journal title
CERAMICS INTERNATIONAL
ISSN journal
02728842 → ACNP
Volume
25
Issue
6
Year of publication
1999
Pages
551 - 559
Database
ISI
SICI code
0272-8842(1999)25:6<551:IBGCPA>2.0.ZU;2-#
Abstract
Interdependence of green density and corresponding powder agglomeration and their influence on the sintering behaviour of commercial fine zirconia pow ders under a constant rate of heating (non-isothermal sintering) were inves tigated. Agglomeration of the powder was controlled by different time perio ds of ball-milled processing and was defined as the size ratio of sedimenta tionally measured particle size to the size of primary particles which were microscopically-determined (hereinafter termed agglomeration parameter or AP). Green compact density shows to be approximately linearly related to po wder agglomeration under identical consolidation technique, which is decrea sed with increasing degree of agglomeration. Both the green density and pow der agglomeration affect sintering behaviour over entire sintering schedule . For a given AP the shrinkage rate reduces with increasing green compact d ensity and vice versa, which is consistent with the literatured reports. Th e experimental results also showed that compacts with identical starting de nsity showed a lower shrinkage rate when the compacts contained less agglom eration (i.e. low AP) than does for high-AP compacts. However, a higher end -point density can be obtained for low-AP compacts, suggesting a better pac king structure of the powders. The use of agglomeration parameter defined c urrently, which is taken as an indication of the level of powder agglomerat ion in commercial fine ceramic powders, is likely to provide some useful un derstanding in characterising the sintering behaviour and possibly potentia l evolution of sintered microstructure on sintering. (C) 1999 Elsevier Scie nce Ltd and Techna S.r.l. All rights reserved.