Kinetics study in Ti–Fe2O3 system by electro-thermal explosion method

• Electro-thermal explosion (ETE) approach was used to study kinetics of thermites.
• Apparent activation energies (Ea) of Ti + Fe2O3 thermite reactions were obtained.
• The influence of oxide precursor's morphology on Ea was investigated.
• The ETE is shown to be a feasible mode for production of metastable binary phases.

High-temperature (1300–1600 K) kinetics of titanium (Ti) and iron (III) oxide (Fe2O3) heterogeneous thermites were investigated using electro-thermal analysis (ETA) technique. Three different grades of Fe2O3 powder precursors were mixed separately with Ti powder (Ti:Fe2O3 = 13.34 M ratio) and were subjected to ETA experiments. For the first time a high-speed infrared thermal imaging system was also applied simultaneously with ETA to explore temperature-time history of the reaction process. Obtained ETA results show that Ti + Fe2O3 thermite reaction systems exhibit apparent activation energies in the range of 60–100 kJ/mol. The reaction mechanism for Ti/Fe2O3 thermites is also discussed. The Ti–Fe2O3 thermite reaction involves several steps such as reduction of Fe2O3 by Ti with formation of Fe and TiO2 phases, followed by formation of the Ti2Fe intermetallic metastable phase. Statistical treatment of experimental data shows that ETA is a sensitive and accurate technique for kinetics study of high-temperature heterogeneous thermite reactions.