Formation of equiaxed zone in castings

The formation of the equiaxed zone was examined using a transparent succinonitrile–ethyl alcohol solution. The equiaxed crystals were found to be formed by detachment of dendrite arms owing to the convective flow of the bulk liquid. In the early stage of solidification, convection originates from the temperature differences in the liquid, and, in the later stage, from the floating up of alcohol enriched liquid. ejected from inverse V segregate channels in the mushy zone into the bulk liquid ∼ When the superheat of a pouring solution is small, free crystal formation occurs in the liquid adjacent to the mould wall during and immediately after pouring.