Investigation of the induction heating behavior of aluminum particles under different filling structures for electromagnetic tapping

To achieve rapid melting of the blocking alloy during the electromagnetic tapping, hot-state physical simulation experiments were carried out to investigate the feasibility of using aluminum particles as the core filling material. The induction heating behaviour and melting mechanism under different filling structures were also analysed and discussed. The results revealed that graphite can promote the temperature rise of aluminum particles with weak electromagnetic coupling. When a graphite outer ring is introduced, the heating rate increases significantly, through which the temperature reaches about 700°C within 30 s and 1238°C after 5 min, while the central region still cannot fully melt within a short time because of the skin effect. Based on a comprehensive evaluation of all performance indices, the graphite outer ring–graphite rod–aluminum particles composite structure exhibited the most favourable melting performance under the present experimental conditions. This structure enables more efficient and uniform melting of the blocking alloy layer within a short time, which provides a basis for optimising filling structures and realising the purification casting of molten steel.