Fe2O3/aluminum thermite reaction intermediate and final products characterization

Abstract

Radial combustion experiments on Fe 2 O 3 /aluminum thermite thin circular samples were conducted. A stoichiometric (Fe 2 O 3 + 2Al) and four over aluminized mixtures were tested. The combustion products were characterized by X-ray diffraction and Mössbauer spectroscopy and the influence of Fe 2 O 3 /aluminum ratio on their composition was assessed. The main products were identified as alumina (␣-Al 2 O 3 ) and iron (Fe). A significant amount of hercynite (FeAl 2 O 4 ) was detected, decreasing with the aluminum excess in the reactants. Close to the sample/confinement interface, where reaction quenching occurs, a non-stoichiometric alumina (Al 2.667 O 4 ) was observed, being its XRD intensity correlated to the hercynite amount. Fe 3 Al intermetallic phase was found in the products of over aluminized mixtures. A reaction mechanism was proposed comprising: (i) Fe 2 O 3 reduction to Fe 3 O 4 and FeO; (ii) Al oxidation to Al 2 O 3 ; (iii) interaction of the remaining Al with Fe 3 O 4 and FeO with formation of iron-aluminates (hercynite) and iron; (iv) for the over aluminized mixtures, incorporation of Al into the iron-aluminates takes place with the formation of iron and alumina and, in parallel, Al reacts with iron to produce intermetallics.

Modelling and simulation of Fe2O3/Aluminum thermite combustion: Experimental validation

“…1 and Table 1). Chemical and physical characterisation of reactants, and mixtures preparation procedure were presented in previous papers (Durães et al, 2006a(Durães et al, , 2006b). Reactant mixtures were compressed in a stainless steel circular box with an inner PMMA lid (vd.…”

“…The obtained radial combustion propagation profiles, rates and temperatures were discussed in Durães et al (2006a). Finally, the mixtures combustion products were collected and characterized by X-ray diffraction and Mössbauer spectroscopy (Durães et al, 2006b). …”

Ignition Behavior of Al/Fe2O3 Metastable Intermolecular Composites

“…Fan et al [28]reported that the value of E a by Starink method was 145 kJ/mol for the thermite reaction. Bulian et al [31].found the nearest value of 247.76 kJ/mol for the similar nano thermite reaction applying Ozawa method.…”

“…Sarangi et al [27] investigated this system using different Al percent and studied its reaction kinetics. Duraes et al [28] studied the reaction intermediate and final product characterization of Al/Fe 2 O 3 system taking various molar ratio of both the constituents. Mei et al [29] made an interesting investigation for the kinetics and combustion mechanism of the reaction as given in Eq.…”

Rocket-borne Lithium ejection system for neutral wind measurement

“…The thermite reaction is usually initiated by a pyrotechnic device and hot ferric liquid is generated by the chemical reaction (Frolov and Pivkina, 1997;Duraes et al, 2007). The temperature of the chemical products usually reaches 2300 K and is enough to produce a rapid phase change from the solid to the gas phase.…”