High-strength aluminum alloys became the key structural materials of various applications. Because aluminum alloys with the high contents of alloying element have the range of the melting became wide, the existed phases with high volume fractions and large grain at grain boundary is produced by the direct chill casting. In order to reduce surface crack and internal defect of the high strength aluminum ally billets during casting, the electromagnetic stirring technique was adopted.
It is found that the crack is often formed in DC casting, the billet without crack defects is obtained in electromagnetic stirring casting. The temperature gradient of the melt between the surface and center is about 15~20K during DC casting, in the applied electromagnetic stirring field, the temperature gradient and the pool depth was remarkably reduced. Also, the required time for homogenization treatment of electromagnetic stirred billet could be reduced.