1996 Volume 82 Issue 10 Pages 829-834
In order to clarify the formation mechanism of V-type segregation, flow phenomena was examined by using two kinds of samples: solid particle-water mixture and aqueous solution of NH4Cl. The former was used to simulate the slipping phenomena of equiaxed crystals in the mushy zone and the latter to simulate the remelting of mushy zone of ingot. These samples were sucked down through the outlet located at the center of the bottom of a cavity with constant velocities, which is called artificial suction. Most particles or equiaxed crystals and liquid in the upper part of the cavity moved down vertically. The V-type movement or slipping of particles were not observed. In the case of aqueous solution of NH4Cl, equiaxed crystals moved down vertically during the artificial suction and the V-type movement or slipping were not observed. However, the V-type segregation were formed in the mushy zone. It is concluded that the V-type segregation were not formed by the slipping phenomena but by the remelting.