Improvement of sintering and microstructural homogeneity of a diphasic mullite

Effect of seeding of boehmite-colloidal silica mixture with aluminium sulph ate-colloidal silica mixture on its mullite formation and sintering behavio urs and microstructural development was studied. It was observed that early forming mullite crystallites from aluminium sulphate-colloidal silica mixt ure acted as nuclei for boehmite-silica mixture and improved mullite format ion behaviour. Although seeding reduced viscous flow sintering behaviour of boehmite-colloidal silica mixtures its solid state sintering behaviour was improved as seeding reduced mullite grain size and prevented the occurrenc e of fine intragranular pores within mullite grains. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.