Crystallization Structures of the Ingots of Aluminium and its Alloys (Report 2)

Aluminium alloys were melted in a mild steel case and were solidified at various degrees of melting temperatures and of cooling speed. And crystallization structures of the ingot thus made have been examined. Aluminium alloys put to the test were made of the same Aluminium blocks given on Vol. 6, No. 2, in adding them Cu 4%, or Cu 4% and Mg 1%. The result was that these alloys, as well as Aluminium blocks, changed from granular to columnar crystals, but unlike the latter a zone of radiant crystals existed. Aluminium alloys containing Cu 4% are more apt to becomd granular crystals than Aluminium blocks, and Aluminium alloys containing Cu 4% and Mg 1% are more apt to become columnar than. Aluminium alloys containing Cu 4% only; …Aluminium alloys containing Cu 4%, on being added Mg also, come to resemble the structure of Aluminium blocks. From results of these experiments, the relation among super-cooling temperature, crystal nucleus and crystallization velocity of crystals has been referred to.