Overall shape of sintered alumina compacts

Ozkan N., BRISCOE B.

CERAMICS INTERNATIONAL, vol.23, no.6, pp.521-536, 1997 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 23 Issue: 6
  • Publication Date: 1997
  • Doi Number: 10.1016/s0272-8842(96)00065-x
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.521-536
  • Middle East Technical University Affiliated: No


The extent of the thermally induced shrinkage during sintering of nominally homogeneous ceramic compacts depends upon the green density; compacts with a low green density shrink more than those with a higher density. Therefore, shape distortions of compacts with variable density during their sintering is inevitable. The overall shapes of various sintered alumina compacts, prepared using different types of alumina agglomerates, is described. The agglomerates were prepared using organic polymer [poly(vinyl alcohol) (PVA) and poly(ethylene glycol) (PEG)] binders and the influence of the particle agglomerates size and the water content in the agglomerates is considered. The extent of the shape distortions in the cylindrical sintered compacts were reduced with the application of lubricants to the die walls. The agglomerate properties are shown to affect the overall shape of the sintered compacts significantly. The compacts, produced using the wet (plastisized) agglomerates, have the smallest shape distortions. A prediction of the sintered shape evolution is obtained using a first order model. The model predicts that the shape distortions in the sintered compacts increase with the increasing of the sintered density and a good agreement between the predicted and measured data is demonstrated. (C) 1997 Elsevier Science Limited and Techna S.r.l.