Intermediary phases formation in Fe–Al–Si alloys during reactive sintering

Formation of intermediary phases during reactive sintering of Fe–Al–Si powder mixtures at 1100 °C was studied in this work. Results show significant difference from already presented results achieved at lower sintering temperatures. Phase composition is closer to the equilibrium phase diagram. Silicon additions up to 10 wt.% produce binary Fe–Al phases, further increase of silicon content leads to the formation of FeSi silicide and Al2Fe3Si3 ternary phase. Binary FeSi40 alloy contains FeSi and FeSi2. Porosity is reduced by addition of silicon. The lowest porosity was achieved when 10 wt.% of silicon was added. Formation of binary Fe–Al phases is controlled by aluminium diffusion through the layer of intermetallics. In Fe–Al–Si system, the controlling process is the reaction producing ternary intermediary phases. The highest wear resistance was determined in FeAl30Si10 alloy with single-phase FeAl structure. An increase of silicon content reduces the wear resistance although hardness increases.