Growth of tabular α-Al2O3 grains on porous alumina substrate
Journal
Journal of the American Ceramic Society
Journal Volume
91
Journal Issue
2
Pages
595-598
Date Issued
2008
Author(s)
Abstract
Gradient, porous alumina ceramics were prepared with the characteristics of microsized tabular α-Al2O3 grains grown on a surface with a fine interlocking feature. The samples were formed by spin-coating diphasic aluminosilicate sol on porous alumina substrates. The sol consisted of nano-sized pseudo-boehmite (AlOOH) and hydrolyzed tetraethyl orthosilicate [Si(OC2H5)4]. After drying and sintering at 1150°-1450°C, the crystallographic and chemical properties of the porous structures were investigated by analytical electron microscopy. The results show that the formation of tabular α-Al2O 3 grains is controlled by the dissolution of fine Al 2O3 in the diphasic material at the interface. The nucleation and growth of tabular α-Al2O3 grains proceeds heterogeneously at the Al2O3/glass interface by ripening nano-sized Al2O3 particles. © 2007 The American Ceramic Society.
Type
journal article