Phase transition in the Fe–V system

Abstract

Abstract Fe – V binary alloys with different vanadium concentrations (4 to 55 at.%) are arc melted and systematically characterized by means of; (1) differential thermal analysis, (2) optical and scanning electron microscopy coupled to an energy dispersive X-ray microprobe analysis, (3) quantitative X-ray fluorescence spectrometry, and (4) X-ray diffraction. The present work exhibits the solidification sequences according to the observed microstructures for Fe – V synthesis alloys. For the first time, a metastable -phase was observed in Fe rich alloy (4 at.% V). The phase transition is clearly shown. It takes place at 1320°C for the alloy V1 (4 at.% V). For higher vanadium contents (55 at.% V maximum), the -phase is no longer observable. The phase transition is also shown. The -phase precipitates directly by a congruent reaction from the -solid solution. It occurs at 1090°C for the alloy V3 (25 at.% V) and increases with the vanadium content (ranging from 25 to 55 at.% V). These results are plotted on the accepted Fe – V phase diagram.