Effect of the Filling Ratio on the Solidified Structure in Horizontal Centrifugal Casting Process

The effect of free surface on the formation of solidified structure in horizontal centrifugal casting process has been studied. The filling ratio of the transparent organic substance in the glass cell was changed from 70 to 100%. In case of low filling ratio, the columnar and equiaxed zone formed. On the other hand, when the filling ratio exceeded 95%, no equiaxed grain was observed. The equiaxed zone ratio decreased with increasing the filling ratio. Increasing the filling ratio leads to the decreasing the free surface area and this makes the liquid motion stable. This has been confirmed by the model experiment using silicone oil and plastic particles. Therefore, free surface wave considerably influences on the evolution of solidified structure. Especially, free surface wave affects the equiaxed grain formation and their travelling for a long distance.