Production of Fe-B compounds via the self-propagating high-temperature synthesis technique

This study investigated the conditions for self-propagating high-temperature synthesis (SHS) of FeB. Hematite (Fe2O3) and magnetite (Fe3O4) powders were used as iron sources, and phases generated under varied aluminum stoichiometries were identified. The SHS reactions produced loose powder products. Significant levels of impurities were detected in both experimental sets along with the FeB compounds. XRD analysis of the SHS products revealed the presence of only Fe2B and MgO phases. Removal of Mg-based impurities was carried out through HCl leaching at different concentrations. The targeted FeB structure was obtained as intended in the experiments. Optimal conditions were identified as a reduction of the hematite-boron oxide mixture with 110 % stoichiometric Mg and subsequent leaching in 8 M HCl.