Devitrification of Mechanically Alloyed Fe-Nb System: Mössbauer Study of the Intermetallic Phases

Abstract

Intermetallic phases in the Fe-Nb system have been obtained as products of the devitrification of a homogeneous amorphous FeNb alloy prepared by mechanical alloying. Besides FeNb Laves and FeNb intermetallic phases, α-Fe phase has been detected by X-ray diffraction (XRD). Hyperfine parameters for both FeNb and FeNb intermetallics have been obtained from Mössbauer spectroscopy in correlation with phase identification from XRD results. Thermomagnetic measurements show changes in the Curie temperatures of the amorphous and FeNb phases during the crystallization, due to compositional variations related to the developing of the α-Fe phase. Kinetics of the crystallization process has been analyzed using the classical Johnson-Mehl-Avrami-Kolmogorov kinetic theory in both isothermal and non-isothermal regimes.