Formation of Mg–Al–Ti/MgO composite via reduction of TiO2

This paper investigates the possibility of reduction of TiO2 through the mechanical alloying of Mg and TiO2 powders. Elemental Mg and Al powders were first mixed with TiO2 according to the nominal composition of Mg5wt.%–Al17.15wt.%–TiO2. The powder mixture was mechanically milled in a planetary ball mill for different durations. Two types of DSC curves have been observed. The unmilled powders showed no reaction when heated to about 500 °C, while an exothermic reaction in the mechanically milled powders was observed at about 390 °C. Further investigation of the heat treatment of the mechanically milled powders showed the complete disappearance of TiO2 and the formation of MgAl2O4 after annealing at 400 °C, implying that reduction of TiO2 has occurred via the mechanical activation and annealing processes.