Effect of β-spodumene on the phase development in an alumina/aluminium-titanate system

The effect of β-spodumene additions on the in situ phase formation and abundances in an Al2O3–Al2TiO5 system in the temperature range 1000–1400 °C has been studied by neutron diffraction and differential thermal analysis. Results show that β-spodumene began to decompose by phase separation and partial melting at 1290 °C, followed by complete melting at 1330 °C. Formation of Al2TiO5 was observed to occur at 1310 °C and its abundance increased with temperature. The addition of β-spodumene as a sintering aid did not cause its reaction with alumina or rutile to form additional phases. Addition of β-spodumene in excess of 5 wt% resulted in pronounced vitrification, which partly recrystallised when cooled to room temperature. The temperatures of Al2TiO5 formation and melting of β-spodumene are consistent with the results of differential thermal analysis.