Effect of reactive sintering conditions on microstructure of Fe–Al–Si alloys

In this work, the dependence of microstructure of Fe–Al–Si alloy on conditions of reactive sintering was studied. It was shown that heating rate strongly affects the structure of this alloy. The microstructure consisting of uniformly distributed Al2Fe3Si3 particles in Al2FeSi matrix can only be obtained in this material by rapid heating (over 300 K min−1). Sufficient reactive sintering temperature to obtain Al2Fe3Si3–Al2FeSi two-phase structure is 750 °C. Further increase of the reaction temperature reduces porosity but causes a growth of Al2Fe3Si3 particles. Reactive sintering process is completed during less than 10 min in the investigated material. Temperatures over 1050 °C produce material composed of FeSi, FeAl and Al2Fe3Si3 phases. However, strongly exothermal reaction of FeSi formation causes melting of the sample.