Synthesis and characterization of Cordierite-Mullite ceramics using different andalusite sources

In this research, in-situ cordierite mullite ceramics were synthesized using different sources of andalusite, as well as talc, calcined alumina and silica. The formulations were designed so that ۷۰ wt% cordierite and ۳۰ wt% mullite can be formed in-situ during firing. Physical and mechanical properties, phase analysis and microstructure of the samples were investigated after firing at different temperatures (۱۳۰۰-۱۳۷۵ oC). The results showed that cordierite-mullite ceramics can be synthesized by carefully controlling the selected raw materials. However, the impurities of raw materials (especially Mica minerals in domestic andalusite compared to imported one) affected the formation temperature and quantity of mullite and cordierite phases, so that the amount of the main phases decreased with the increase of glassy phase. On the other hand, using higher purity imported andalusite, the complete formation of cordierite and mullite phases required higher sintering temperatures. The best composition in terms of properties was obtained by using foreign Andalusite fired at ۱۳۷۵ oC for ۳ hours.

کلیدواژه ها:

Andalusite ، Cordierite ، Mullite