EFFECT OF HIGH MAGNETIC FIELD ON THE CRYSTALLIZATION OF MELT-SPUN FE-PT-B AMORPHOUS ALLOY

The crystallization of melt-spun Fe - Pt - B amorphous alloy with a thickness of 20 µm in steady high magnetic field (HMF) was investigated. The intensity of the applied magnetic field is 0-10 T along with the ribbons annealed at temperature ranging from 673 K to 873 K. The direction of the performed magnetic field is perpendicular to the direction of surface velocity of the Cu wheel. The thermal magnetic properties of the samples were obtained by the thermal gravity analyzer with a magnet attached to the outside of the furnace filled with flowing inert gas. The phase transformations of Fe - Pt - B amorphous alloy on heating with and without the steady HMF were studied by X-ray diffractometry together with the melt-spun ribbon. The average grain size of the samples annealed in HMF was about 10 nm calculated from the XRD patterns. The HMF was thought to be effective on the refinement of nanograins which were produced by the crystallization of the amorphous ribbon during the annealing process.