Crystallization behavior of Fe84B10C6 amorphous alloy under high magnetic field

Abstract High magnetic field is a powerful tool in controlling the crystallization processes of amorphous alloys. The main objective of the paper is to clarify the effect of high magnetic field on the crystallization of Fe84B10C6 amorphous ribbons. The non-isothermal crystallization kinetics of the as-spun amorphous alloy was firstly investigated using a continuous differential scanning calorimetric (DSC) technique, then the isothermal crystallization processes of the amorphous alloy were performed under a magnetic field of 0 or 12 Tesla (T). The annealed samples were characterized using DSC, X-ray diffraction, and transmission electron microscopy. The JMA exponent n at the initial stage of the first crystallization reaction is about 2.5. The crystallization starts with a homogenous nucleation, then the nucleation rate continuously decreases to zero, and the crystallization proceeds with the growth. The α-Fe precipitates from the Fe84B10C6 amorphous matrix at the isothermal annealing temperatures investigated, and the 12 T high magnetic field enhances the precipitation of α-Fe. The volume fraction and number of the precipitated α-Fe crystals in the alloys annealed under the 12 T high magnetic field are greatly larger than those in the alloys annealed at the same temperature without the magnetic field. However, the magnetic field has no obvious influence on the average grain size of the α-Fe crystals. The mechanism of the high magnetic field on the crystallization of the Fe84B10C6 amorphous alloy is to enhance the nucleation of the α-Fe.