In-Situ Observation of Horizontal Centrifugal Casting Process using a High-Speed Video Camera

A high-speed video camera was installed in a model experimental apparatus for horizontal centrifugal casting process. Using this newly developed apparatus, in-situ observation has been performed with transparent organic substances. The former data for the loci of an equiaxed grain observed at the rotation rate of 250 rpm indicated like a line graph, because the event was recorded with 30 frames per second (fps). On the other hand, the present loci of an equiaxed grain recorded with 500 fps is smooth and very easy to characterize. This installation enabled us to rotate the experimental apparatus up to 1000 rpm, where the acceleration due to centrifugal force is the same order of magnitude as the real production process. The fluctuation of free surface and the movement of the equiaxed grain has been precisely characterized by the high-speed video camera up to the rotation rate of 1000 rpm. It has been found that the fluid flow can be stabilized as the rotation rate increased. Therefore, the formation of equiaxed grains decreased and the length of columnar dendrites increased with increasing rotation rate. These observation has been first achieved in this study because the experimental apparatus for horizontal centrifugal casting process has been equipped with the high-speed video camera.