Crystallization of the metallic glass Fe78B13Si9

The microstructures and kinetics with heating for an amorphous Fe₇₈B₁₃Si₉ alloy were studied by X-ray diffraction, transmission electron microscopy, differential thermal analysis and differential scanning calorimetry. The first crystallization takes place by the simultaneous formation of -(Fe,Si) and Fe₃B having the shapes of dendrite and spherulite, respectively. Metastable Fe₃B then transformed into a stable phase of Fe₂B at a higher temperature. The activation energy for crystallization and the Avrami exponent were determined. It was found that crystallization behaviour in Fe₇₈B₁₃Si₉ is controlled by nucleation rather than growth.