Twin-strand technology and microstructure analysis for the electromagnetic near net-shape casting of aluminum alloy

In order to increase the production efficiency, the twin-strand technique of electromagnetic casting (EMC) in the aluminum industry for the casting of near net-shape products was investigated, and the corresponding apparatus were designed. The distribution of magnetic field inside the series-wound inductor was measured. From this result, the solidification front of melt can be decided. The key parameters such as liquid column, casting speed and flow rate of cooling water were obtained, respectively. The cylindrical ingots with diameter of 240 mm were cast by the twin-strand EMC unit. The metallography of 2024 aluminum alloy was studied and compared with the specimens from direct chill casting (DCC) ingots. The mechanism of grain refinement was discussed by comparing the heat transfer and the solidification characteristics of EMC and DCC.