Abstract: Observation in-situ of crystal growth of the transparent model alloy is an effective method to study solidification of crystal. An apparatus system to study the process of crystal growth was designed, which includes 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 were experimentally studied at different growth condition parameters. 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.

Key words: unidirectional growth, real-time observation, microconvection, downstream alternation