A new approach to producing large-size AA7055 aluminum alloy ingots

Abstract

In this paper, Low frequency electromagnetic field and air knife are applied simultaneously to produce large-size AA 7055 aluminum alloy ingots during DC casting. Moreover, the effects of low frequency electromagnetic field and air knife on the macro-physical fields during DC casting and the microstructure and crack in the ingots are studied and analyzed by the numerical and experimental methods. Comparison of the calculated results indicate that applying electromagnetic field can modify the direction and increase the velocity of melt flow and homogenize the distribution of temperature in the sump, and applying air knife can homogenize the distribution of temperature and decrease the stress and strain in the solidificated ingots. Further, the microstructure of the billet is refined remarkably and the crack is eliminated by applying electromagnetic field and air knife during DC casting because of modification of the macro-physical fields.