Investigation on the reactions sequence between synthesized ilmenite and aluminum

Fe-Al2O3/TiC composites have features of which we can refer to: good strength, toughness, wear resistance, high temperature strength and light weight. It can also be used as cutting tools. Some researchers have used ilmenite, aluminum and carbon to produce these composites. However the formation mechanism and reaction sequences are not clear enough. In this research, the first step of reactions was investigated by studying the binary phase between aluminum and ilmenite. At first, ilmenite was synthesized, and then the critical temperatures due to the reactions occurring in the ilmenite-aluminum powder mixture were determined by DTA. The milled and pressed samples of synthesized ilmenite and aluminum with molar ratio of 1:2 were heat treated at 740 °C for 3, 12, 15, 24 and 72 h and at 1000 °C for 24 h. The final products were analyzed with XRD, SEM and EDS. The results show that after the melting of aluminum, the reaction between ilmenite and molten aluminum starts, leading to formation of Fe and TiO2. It is found that the tendency of FeO to reduce with aluminum is more than TiO2. Therefore, FeO reduces to Fe while the TiO2 remains unchanged. By consumption of the raw materials, Fe and TiO2 react with remained aluminum, resulting in the formation of spherical Fe2Ti in the TiO2 and Al2O3 matrix.