Effect of Fe2O3 as an accelerator on the reaction mechanism of Al–TiO2 nanothermite system

Abstract

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.