Synthesis of FeSi-Al2O3 Composites by Autowave Combustion with Metallothermic Reduction

Fabrication of FeSi-Al2O3 composites with a molar ratio FeSi/Al2O3 ranging from 1.2 to 4.5 was conducted by the self-propagating high-temperature synthesis (SHS) method. The reaction involved metallothermic reduction Fe2O3 and SiO2 Al chemical interaction Fe Si. Two combustion systems were examined: one contained thermite reagents 0.6Fe2O3 + 0.6SiO2 2Al, other had 2Al mix different amounts Si powders. A thermodynamic analysis indicated that oxide precursors sufficiently exothermic sustain in mode. SHS carrying out co-reduction less exothermic, applied synthesize products = 1.2–2.5, while reducing only more energetic adopted for 2.5–4.5. Moreover, former larger activation energy, i.e., Ea 215.3 kJ/mol, than latter, 180.4 kJ/mol. For both systems, wave velocity temperature decreased increasing FeSi content. Formation situ achieved. Additionally, trivial amount aluminum silicate detected high contents due dissolution into Al2O3 during process.