Abstract
To produce high-quality materials, a large number of studies have been carried out for the solidification and melting processes of metals and semiconductors in both terrestrial and space environments. This paper aims to describe a series of experiment on the effect of the thermocapillary convection upon the directional solidification in a liquid layer with the free surface in case of stationary and growing solid-liquid interface (SLI). If no free surface exists, the SLI is vertical and straight. On the other hand, with the free surface, the SLI is inclined against the wall-normal direction due to the thermocapillary convection. It is also found that even if the growth rate of the SLI at the free and bottom surfaces is equal, a distinct difference is observed in the solidification morphology between the both surfaces. At the top surface, we found a cellular morphology with a secondary perturbation, which was not observed in experiments hitherto.
