The Effects of Low Frequency Electromagnetic Field on the Macro-physical fields, Microstructure and Crack of the Super-high Strength Aluminum Alloys during DC Casting

• 1、Key Laboratory of Electromagnetic Processing of Materials of Ministry of Education, Northeastern University

Abstract：Low frequency electromagnetic casting process is used to produce the super-high strength Al-10Zn-2.3Mg-2.4Cu-Zr aluminum alloys in this research. Moreover, the effects of low frequency electromagnetic field on the macro-physical fields (flow field, temperature field and stress-strain field) in the semi-continuous casting process of aluminum alloys and the microstructure and crack in the billets are studied and analyzed in detail by the numerical and experimental methods. Comparison of the results for the macro-physical fields in the LFEC process with that in the conventional DC casting process indicate the following characters due to the application of electromagnetic field: a vigorous forced convection of the melt; an entirely changed direction of melt flow; a remarkably increased velocity of melt flow; a uniform distribution of temperature; a decreased gradient of temperature; the elevated isothermal lines; the reduced sump depth; the decreased stress and plastic deformation. Further, the microstructure of the billet 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.

Keywords： aluminum alloy casing low frequency electromagnetic field crack microstructure