Effect of Fe2O3 as an accelerator on the reaction mechanism of Al-TiO2 nanothermite system
Thermite reactions between aluminum and metal oxides could lead to the formation of intermetallic matrix composites used in high-temperature industrial applications. Thermite reaction in Al-TiO2 system needs a considerable amount of energy to take place by mechanochemical or by the combustion synthesis (CS) method due to the low amount of reaction enthalpy in Al-TiO2 system. In this study, Fe2O3 was chosen as a accelerator for this system, to generate a high amount of heat which could be released between Fe2O3 and Al, leading to a more convenient reaction between Al and TiO2 in the CS process. The results of XRD, SEM, and DSC analyses indicated that both the mechanical activation of Al-TiO2 system in a high-energy ball mill and the Fe2O3 addition led to considerable effects of reduction in the reaction temperature and increase in the reaction intensity in Al-TiO2 nanothermite system. Finally, it was shown that Fe3Al intermetallic compounds as well as γ-AlTi and alumina phases in the final products were formed after the CS of the milled powders.