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Information × Registration Number 0201U001354, 0197U014940 , R & D reports Title Kinetics and mechanisms of the relaxation processes in a metallic glass near the glass transition tempreture popup.stage_title Head Tkach V.I., Registration Date 31-01-2001 Organization A.A. Galkin Physics and Engineering Institute of National Academy of Science of the Ukraine popup.description2 The effect of the main parameters of the melt-spinning process, such as wheel speed, the ejection pressure and the melt temperature has been studied by the original thermoelectric technique. It has been found that the rate of cooling depends on the ribbon thickness (d) as d^-3.1 when the lftter value is changed due to variations of the wheel speed. It has been shown that both the ejection presure increasing and the superheat decreasing result to simultaneous growth of the ribbon thickness and of the rate of cooling. By X-ray diffraction, small-angle X-ray scattering, differential thermal analysis and resistometry it has been found that structural relaxation in metallic glass Fe40Ni40P14B6 is a multi-stage process, which under continuous heating includes relief of the quenching stresses, decreasing of the excess free volume concentration and increasing of the inhomogeneities of concentration at the mesoscopic scale. The lftter process takes place at temperatures above the glass transition temperat ure. A theory based on Landau-Khalatnikov equation which considers the excess free volume as nonconserved order parameter has been developed. The technique for evaluation of the thermodynamic and kinetic parameters which control crystallization of amorphous phases. The temperature dependencies of the interfacial diffusion coefficient and the specific free energy of the melt-nucleus interface were determined for Fe40Ni40P14B6 metallic glass. It was found that the size of nuclei which nucleate during crystallization of metallic glasses are about two order of magnitude smaller than average radius of the concentration fluctuations which form at the final stages of structural relaxation. Product Description popup.authors popup.nrat_date 2020-04-02 Close