Effect of ulexite on thermal and mineralogical properties of mullite-zirconia composite

This study focuses on the effect of ulexite additive on thermal and mineralogical properties of mullite-zirconia composite by reaction sintering process. For this purpose, two different compositions were prepared: one containing only zircon, alumina, and kaolinite, the other containing zircon, kaolinite, alumina, and ulexite. These two mixtures were compared using DTA and XRD analyses according to some physical properties. It was determined through both DTA and XRD analyses that ulexite addition to mullite-zirconia composite synthesis lowers reaction temperature. While zirconia in the mixture without ulexite subsists up to 1550 °C, it decays completely in the composition with ulexite at 1450 °C and at this temperature, the composite is observed to be synthesized.