Real-time Observation Of The Crystal Growth Process Of The Optical Research

In-situ observation of crystal growth of the transparent model alloy is an effective method to study solidification of crystal. It is great significance to control crystal organizational structure and recognize crystallization mechanism. Crystal growth is a dynamic process which is composed of mass and heat transport and interface kinetics, but these transports are usually controlled by the convectie effects in crystal growth. Because the convective effects play an important role in crystal growth, the study of the convective effects in crystal groeth seems much more active recently.In this paper, an apparatus system to study the process of crystal growth is designed, which include the room of crystal growth in unidirectional solidification and the observation and measurement apparatus. With this experiment system, the morphology of growing interface of Succinonitrile-5wt% Ethanol as a transparent model alloy are experimentally studied at different growth condition parameters.It was showed that the cell formed in the interface of small amplitude when the interface of smooth was perturbed. After branching of the tip, elimination and competition, the stable cell formed; In a strong amplitude, branching of the tip was not happened in the interface of smooth. Then there was only elimination and competition developed rapidly to form stable dendrite in the interface. The interface was unstable when the cell and dendrite coexistence, cell changed into dendrite in company with rapid speed.It is found that the effect of the buoyancy-driven flow and the microconvection in the crystal growth process can cause downstream alternation of the cell growth direction.