Barannikov O. Influence of thermal prehistory and external effects on the crystallization kinetics melts

The dissertation is devoted to the experimental stady of the Influence dominance of thermal prehistory (a melt overheating, the time of isothermal holding, and cooling rate) and external effects on the crystallization kinetics of Pb, Sn, Zn, Cd, Bi, HO, S, melts and Sn-Bi, Bi-Sb binary alloys. For the first time was fiwed a jumpwise dependence of supercooling on overheating as a function of the melting temperature. The constitution diagrams of Sn-Bi, Bi-Sb are drawn, precrystallization supercooling being shawn. There is studied the kinetics of phase transformations of the first order in an elementary sulphur, that is of polymorphous transitionsand melting-crystallization processes. There is found out that if sulphur overheating increasesas to temperature of a direct transformations up to a melting temperature, temperature of a revers transformation falls exponentialy. There is fixed that for Bi and HO a permanent magnetic field of the up to 0,5Tl indaction makes a supercolling quantity, an incubation period of nucleation and a general time of hardening less. There are determined modes of vibration and stirring of Sn, Bi, Sb melts, under which supercooling and the structure of a crystallizing solid phase change. The results obtained are interoreted from a viewpoint of a clusture-coagulation model of crystallization of a liquid and solid phase structures.