Effect of rapid solidification on microstructure of various Fe 29.5− xSi 70.5− x (0.0≤ x≤3.7) alloys

Abstract

Two rapid solidification processes were applied to various Fe 2Si 5 based alloys. The rapidly solidified structure was examined as a function of Si content by TEM, SEM and XRD. The results were compared with those of slowly solidified alloys. Some metastable phases were formed by rapid solidification and they were dependent on the composition of alloys. A few α+ ϵ eutectic was newly formed with primary α phase in 70.5 at.% Si alloy where no eutectic was expected from the equilibrium phase diagram. The amount of metastable eutectic decreased with increasing Si content. The lattice constants of the rapidly solidified α phase were different from those of the slowly solidified α phase due to the increase of the solubility of Si in α. A supersaturated α single phase was formed in 71.5–72.0 at.% Si alloys.