Ceramics-Silikáty 47 (1) 13-19 (2003)

KINETIC STUDY OF AL₂O₃ SINTERING BY DILATOMETRY

Z. HOLKOVÁ, L. PACH, V. KOVÁR, Š. SVETÍK

Sintering of a-Al₂O₃ powder (particles » 1 µm), boehmite gels (particles » 5 nm) and compositions of a-Al₂O₃, boehmite and graphite has been studied by stepwise (SID) and individual (IID) isothermal dilatometry. Boehmite gel is a high temperature binder and graphite is a pore forming material in the mentioned compositions. Boehmite derived alumina controls the sintering process of compositions if it is present as a continuous phase. Kinetic parameters of sintering (exponent n and apparent activation energy E) indicate different sintering mechanism of a-Al₂O₃ and Al₂O₃ derived from boehmite gels. Porosity of a-Al₂O₃ ceramics can be managed by joint addition of boehmite gel and graphite.

Keywords: Al₂O₃, Boehmite, Sintering, Dilatometry, Ceramic membranes.