Abstract
Molten commercial aluminium was oast in sand mould in the presence of high electric current. Grain refinement was enhanced as the current was increased. In case of alternating external magnetic field, however, there was no proportionality between the refinement and magnetic field strength. The ingot acquired fine equiaxed grains when the magnetic field was about 0.3 kilo gauss. At all other values, ingots showed mixed structure of equiaxed and columnar areas to varying proportions. The ingot cast in this experiment was about 100g.
The behaviour of the 4-kg ingot cast in an experimental semi-continuous casting machine was almost the same. The number of grains/cm2 in both experiments was about 700.
