REACTION-FORMING OF MULLITE CERAMICS USING AN AQUEOUS MILLING MEDIUM

Mullite and mullite/ZrO2 ceramics mere fabricated starting from Si/Al2 O3 and Si/Al2O3/ZrO2 powder mixtures, which mere mixed and attrition m illed with TZP balls in water, Isopressed powder compacts were subject ed to a heat treatment in air, during which the Si was oxidized to SiO 2, At similar to 1410 degrees C, reaction between Al2O3 and SiO2 occur red, resulting in mullite (3Al(2)O(3) . 2SiO(2)). Depending on the com position of the starling powders, the end product was either single-ph ase mullite or a mullite composite, The reaction process was monitored by thermogravimetry and dilatometry. It was found that the microstruc ture and mechanical properties of the reaction-formed mullite ceramics were significantly improved by ZrO2 additions.