Reaction Sintering of Fe-Al-Si Alloys

The present study concerns the production of multiphase alloys of the Fe-Al-Si system using a powder metallurgical approach. Several compositions have been considered based on alpha-Fe, alpha'-FeAl; and alpha"-Fe3Al intermetallic phases. Elemental powder mixtures were compacted and sintered in a dilatometer. In this way, the dimensional changes involved with thermally induced transformations could be followed during continuous heating runs up to the sintering temperature. The effect of heating rate has been considered. The characterization of the final products was based mainly on x-ray diffraction (XRD) analyses, particularly as concerns the quantification of the crystalline phases present in the final products. Grain and porosity morphologies were characterized by scanning electron microscopy (SEM). In this way, clear indications of the reaction and densification processes occurring during the sintering treatments were obtained.