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Information × Registration Number 0205U007236, 0103U000583 , R & D reports Title Development of the physicochemical fundamentals of nucleation of overcooled melts at their crystcrystallizatioin under operating of electromagnetic fields popup.stage_title Head Alexandrov Valery Dmitriyevich, Registration Date 12-01-2006 Organization Donbas national akadeny of civil engineering and architecture popup.description2 There has been used a new way of a combined STA and DTA thermocycling to study the kinetics of crystallizing melts. A device for a combined thermal analysis with an automatic heat setting and electromagnetic action on the metal under crystallization has been made. There have been performed experimental researches of the crystallization of the substance melts under different conditions of heat and time treatment and external actions. There have been fixed new exo- and endothermal effects in melting and crystallization, that is a jump- like transition from an equilibrium crystallization to a non-equilibrium explosive one on elementary substances and chemical compounds, and a fluent transition of the this type for the alloys. There have been determined conditions of the heat and time treatment and electromagnetic fields influence on the kinetic parameters of the metals and alloys crystallization. With the help of the STA and DTA methods there has been studied the kinetics of crystallization of alloys inthe system Sn-Bi, Bi, water, resorcinol, pirocatenol and phenol both in the magnetic field and in the absence of the magnetic field. Thermal effects of different phase transformations have been calculated with the help of the DTA method. There has been studied an influence of the melts electrization on the solidification of the aluminum alloys castings. There have been fixed both the magnetic field and convective processes influence on the structure of periodical inhomogeneities in the crystals grown from a melt, and a change of the steel ingots structure under the influence of alternating impact momentums with the help of an electric arc vibrator. The structure of the materials obtained under different conditions of crystallization has been analyzed by the methods of optical microscopy and radiography. The results of the experiments are treated from the viewpoint of the cluster-coagulation model of crystallization. There have been analyzed the thermodynamic parameters of the melts crystallization without external actions and in the electromagnetic fields (metals in the constant magnetic field, dielectrics in the constant electric field), and have been fixed regularities of changing these parameters. A mathematical problem to describe a cooling curve which characterizes the crystallization out of a super-cooled melt has been solved. A heat problem on crystal growth out of a super-cooled melt both without and with a constant electric current passing through a melt has been solved. Product Description popup.authors popup.nrat_date 2020-04-02 Close