Improvement of sintering and microstructural homogeneity of a diphasic mullite

Abstract

Effect of seeding of boehmite-colloidal silica mixture with aluminium sulphate-colloidal silica mixture on its mullite formation and sintering behaviours and microstructural development was studied. It was observed that early forming mullite crystallites from aluminium sulphate-colloidal silica mixture acted as nuclei for boehmite-silica mixture and improved mullite formation 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 occurrence of fine intragranular pores within mullite grains