Alekseechkin N. Kinetics of phase transformations with competetive formation of several .

Object of investigation - processes of phase transformations with competetive formation of several phases. Aim of investigation is development of the theory of competetive nucleation and growth of several phases and its application for calculating kinetics of a supercooled liquid solidification and a metastable crystalline phase spontaneous amorphization. Theoretical and practical results, novelty: The polycluster structure of amorphous solids is shown to be formed as a result of predominance of the volume fraction of non-crystalline clusters over the fraction of crystalline ones. The size distribution functions for clusters and crystals at different cooling rates (Pd82Si18 alloy) are obtained. Also, the temperature regions of formation of amorphous, crystalline and compound amorphous-crystalline solids are determined. Calculation of the kinetics of spontaneous amorphization and subsequent crystallization of Cd43Sb57 alloy high-pressure-phase is carried out; equations of DSC-curves for these processes are derived. The Kolmogorov-Johnson-Mehl-Avrami theory is generalized to the case of several competing phases in spaces of dimensionality D>1.