Reaction-Sintering Mechanisms of Zirconia-Mullite Multiphase Ceramics Prepared from ZrSiO_4/α-Al_2O_3 Mixtures

Mullite-zirconia composites were prepared by reaction-sintering of zircon and α-Al2O3 mixed powders. Densification process as well as formation mechanism of mullite was studied and discussed, and special attention was paid to the effect of mullite seeding on the reactionsintering mechanisms. It is shown that the viscous flow of the non-crystalline may be a dominant densification mechanism prior to the formation of mullite. Mullite seeding has an obvious influence on the forming way of mullite, and a higher relative density of 97% can be obtained when a small amount of mullite seeds (3wt%) are added.