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Abstract: Self-propagating high-temperature synthesis (SHS) was previously proposed as alternative preparation route for Fe–Al intermetallics. However, this process was not optimized and the mechanism and kinetics of the phases'' formation was not fully clarified up to current days. In this work, in situ high energy X-ray diffraction analysis was carried out during the SHS process and the mechanism of the intermetallic'' formation in FeAl25 powder mixture was described during rapid heating and isothermal annealing at 800 °C as well as during a slower continuous heating to 900 °C. During slower heating, the formation of Fe2Al5 and FeAl2 intermetallics starts below the melting point of aluminium. When the heating rate is high, intermetallics are created after melting of aluminium. During long-term annealing, all of the phases can be transformed to FeAl phase when fine powders were applied. Detailed mechanism is proposed in this paper and kinetics of the intermetallics'' formation is described. [Copyright &y& Elsevier]

Abstract: Alloys formed by Fe–Al intermediary phases have lower density than common metallic high-temperature alloys and good high-temperature oxidation resistance. Previously it was proved that silicon additions to these alloys enable to produce them efficiently by reactive sintering and improves the wear resistance. In this work, the oxidation resistance of the novel Fe–Al–Si alloys containing 10–30 wt. % of aluminium and 5–30 wt. % of silicon produced by the reactive sintering technology was tested. Cyclic and isothermal oxidation tests were carried out at 800 °C in air. Tested alloys exhibit excellent oxidation resistance, which increases with silicon content up to 20 wt. %. The reasons are discussed in terms of the phase composition of the oxide layer and the changes in chemical composition under the oxide layer during oxidation. [Copyright &y& Elsevier]