抄録
Dropping molten aluminium droplets weighing about 2 grams into water heated at various temperatures, the process of their solidification has been observed through peeping window set in the side of water tank. The results of observations may be summarized as follows: The shape of the solidified granules depends chiefly on the temperature of water rather than the distanceof falling to the surface of water or the temperature of molten aluminium : If the temperature of water lies between 10° to 30°,the granules obtained showed always a irregular flat form. When the temperature of water was raised to 40∼60°, the major drops solidify in a hollow spherical form ; while, above 60°, keeping the drops in their molten state for a few meters of free sinking in the water, they solidify at last in a compact tad-pole form. From the above observations the present writers have devised a method of obtaining spherical granules of aluminium : The method consists essentially in rotating the molten aluminium droplets, by means of guide plates set in the water tank, during their sinking in the water heated at above 60°.