Effect of particle size distribution on the sinter-crystallisation kinetics of a SiO2-Al2O3-CaO-MgO-SrO glass-ceramic glaze

Sinter-crystallisation kinetics of a glaze with an average particle size of 9.6 mu m, 4.0 mu m and 0.65 mu m, which devitrified anorthoclase and diopside, were studied by non-isothermal techniques. It was confirmed that the crystallisation kinetics could be described by the Johnson-Mehl-Avrami-Kolmogorov model, assuming the Avrami index and activation energy to be independent of particle size. To describe the sintering kinetics, a kinetic model was developed, based on the Johnson-Mehl-Avrami-Kolmogorov model, assuming the effect of temperature on the process rate to be the same as its effect on the inverse viscosity of the glass matrix, and introducing a correction that took into account the difference between the heating rate of the kiln and that of the test piece. The pre-exponential factor of the developed model was confirmed to be proportional to the inverse of glaze average particle size. Glaze sinterability was observed to increase as the heating rate rose and/or average particle size decreased.