  The aim of this work is the development of scientifically based ways of
influencing the process of nucleation of crystallization centres to control the
cast structure and the properties of blanks at the casting stage. The
possibility of controlling crystal nucleation was studied on transparent
modelling media using the droplet method. The dependence of the crystallization
kinetics of drops with a size of 100{\div}200 {\mu}m on the overheating
temperature, the exposure in the overheated state and the degree of
supercooling was established. The curves of the crystallization kinetics of
drops from their melts as the criteria for evaluating the crystallization
process were chosen. The nature of the change in the experimental media
crystallization kinetics curves confirms the assumption about the decisive role
of impurities in the crystallization processes of any alloys. The confirmation
of the hypothesis about the decisive role of impurities in the processes of
crystallization from positions of heterogeneous nucleation is the dependence of
the number of solidified drops with the same diameter on the degree and
duration of their overheating.
