Physical simulation of nucleation and crystallization processes in transparent organic melts

TL;DR

This study develops methods to influence nucleation in organic melts, using transparent models to understand crystallization kinetics and the impact of impurities, aiming to control cast structure and properties.

Contribution

It introduces a new approach to control nucleation in organic melts through experimental modeling and analysis of crystallization kinetics influenced by impurities.

Findings

Crystallization kinetics depend on overheating temperature and supercooling.

Impurities play a decisive role in heterogeneous nucleation.

Overheating duration affects the number of solidified drops.

Abstract

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.