Abstract:The effects of low frequency electromagnetic field on the macro-physical fields in the semi-continuous casting process of aluminum alloys and the microstructure and crack in the billets were studied and analyzed by the numerical and experimental methods. Comparison of the results for the macro-physical fields in the low frequency electromagnetic casting (LFEC) process with the conventional DC casting process indicates the following characters due to the application of electromagnetic field: an entirely changed direction and remarkably increased velocity of melt flow; a uniform distribution and a decreased gradient of temperature; elevated isothermal lines; a reduced sump depth; decreased stress and plastic deformation. Further, the microstructure of the billets is refined remarkably and the crack in the billets is eliminated in LFEC process because of modification of the macro-physical fields induced by the application of low frequency electromagnetic field.

Key words: super-high strength aluminum alloy; low frequency electromagnetic casting; DC casting; macro-physical field; crack; microstructure