Moiseeva T. Two-stage crystallization of the amorphous alloys Fe-B-(Si): kinetics and mechanisms of the formation of crystalline phases

The regularities of non-equilibrium crystallization of amorphous metallic alloys. To establish the main factors governing both thermal stability of amorphous alloys based on the Fe-B-(Si) system, which crystallize via two stage, and the parameters of nanocomposite structures formed at the stage of primary crystallization. Methods of research are X-ray diffractometry, electron and optical microscopy, resistometry, differential scanning calorimetry, magnetometry. For the first time the analytical equations for description of dynamics of growth of nanocrystals in conditions of the diffusion fields impingement and kinetics of primary nanocrystallization as well as two stage crystallization. It is established that the proposed relationships satisfactory describe the experimental data and the values of the effective diffusion coefficients governing the crystal rate growth and thermal stability of the amorphous alloys are estimated. It is shown that kinetics of two stage crystallization at constant rate heating can be described by using of the isothermal equations in which the teal time is replaced by the effective ones with the activation energies of diffusion for each stage. Spheres of use are electrical and instrument engineering.