Fe2O3/aluminum thermite reaction intermediate and final products characterization

By L. Durães, B. Costa, Regina C. Santos, A. Correia, J. Campos, António Portugal. 2007

136 citations recorded by the source corpus.

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 Mossbauer spectroscopy and the influence of Fe 2 O 3 /aluminum ratio on their composition was assessed. The main products were identified as alumina (α-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.

Subfields: Aerospace Engineering, Mechanical Engineering, Mechanics of Materials

View Paper: https://www.semanticscholar.org/paper/c2f2b4107c82fa5f38c4a89921231d2295ee8f2e