Effects of mechanical alloying on the reaction sintering of ZrSiO4 and Al2O3

Mechanical alloying was employed to study its effects on reaction sintering of zircon–alumina mixture to form mullite. Ball milling duration and materials were the main factors to investigate during mechanical alloying. It was found that zircon and alumina became amorphous during mechanical alloying. Ball milling media affects the recrystallization of amorphous phases upon subsequent heat treatment. The temperature of recrystallization of zircon and crystallization of zirconia is 30–70°C higher with alumina ball-milling material than with zirconia ball-milling material, from 940 to 950°C and from 880 to 910°C. Ball milling time had important effect on the temperature of mullite formation. The mullite formation temperature decreased with increasing ball-milling time, from 1556°C for 5 h ball-milling to 1420°C for 40 h ball-milling.