Phase formation and controlled nanostructuring in amorphous Fe80B20 alloy

Abstract

The temperature dependence of the volume fraction of the crystalline phase in Fe80B20 amorphous alloy is calculated using equations from the homogeneous nucleation theory of binary systems. It is shown that the crystallization of Fe80B20 alloy is two-stage, as is confirmed by the experimental data obtained by means of highly sensitive dilatometry and X-ray diffractometry. On the basis of results of calculations performed within the theory of the high-temperature stability of amorphous alloys, two areas of its practical application are proposed: (i) enhancing the thermal stability of amorphous alloys by isothermal annealing in the range of temperatures where crystalline nuclei can transition to the amorphous phase; (ii) controlled nanostructuring of the amorphous state with different modes of treatment. Methods are proposed for obtaining the nanostructured state from the initial amorphous state. Alloys in the nanocrystalline state are obtained, as is confirmed by the results from electron microscope investigations.