Thermodynamic analysis of thermite synthesis for thermoelectric Fe2VAl

For minimizing exergy loss, we studied new synthesizing methods of Fe2VAl for thermoelectric application, theoretically. Fe2VAl has been produced by arc-melting method, which consumed much time and energy. We proposed single thermite synthesis method and double thermite synthesis method, which utilizing exothermic heat of aluminothermic reduction of respective V2O5 and, both V2O5 and Fe2O3 for alloying Fe2VAl through inducing aluminothermic reductions and alloying reaction simultaneously. The exergy analysis showed that the total exergy loss per 1 mol of Fe2VAl was 808 kJ in conventional arc-melting, 562 kJ in proposed single thermite synthesis method using aluminothermic reduction of V2O5, and 1313 kJ in proposed double thermite synthesis using aluminothermic reductions of both V2O5 and Fe2O3. It was found that the proposed single thermite synthesis decreased the exergy loss by 30% of that of conventional arc-melting method and consumed the least exergy due to the effective utilization of sensible heat of V for alloying of Fe2VAl.