EFFECTS OF PARTICLE CLASSIFICATION ON COLLOIDAL PROCESSING OF MULLITE

Rheological behavior of aqueous suspensions of colloidal mullite, gree n densities and sintering behavior of consolidated powder compacts wer e studied on as-received and classified mullite powders of submicromet er sizes. Classification of large particles ( > 1 mum) leads to an inc rease in the viscosity of the suspension and a decrease in the green d ensity as compared with those of the unclassified powder. However, the classified powder is superior to the unclassified powder as for the f ormation of sinterable uniform green texture of narrow pore-size distr ibution and for the increase of driving force of sintering associated with the decrease of average particle size.