Effect of high-energy milling on the formation temperature of the resultant phases in Al/Al2O2/ZrSiO4 system

A powder mixtures of 18.72% wt, 17.67% wt Al2O3 and 63.6% wt zircon were prepared and milled in a planetary ball milled for one up to 10 hours in presence of air. After removal Iron impurity from as-milled samples, they were isothermally heated in temperature range of 1300-1450 0C for one hour in an air atmosphere. After cooling the samples, they were studied using XRD analyses. The XRD and PSA analyses were showed that the size of particles in the mixtures decreased with increasing of milling time and the mixtures became amorphous nature. The isothermal runs observed that pre-milling on the mixtures has great effect, wherever the zircon decomposition temperature and mullite formation temperature decreased to about 1300 0C in a one-hour-milled sample. The amount of tetragonal zirconia increased with increasing in milling time at 1300 0C, however the amount of tetragonal zirconia decreased with increasing of temperature up to 1450 0C. The amount of tetragonal zirconia at 1300 0C in the three hours milled samples was the highest value among all samples.