Effects of an intermittent permanent magnet stirring on the melt flow and grain refinement of Al–4.5Cu alloy

A novel technology, termed intermittent permanent magnet stirring (I-PMS), is proposed to improve the quality of aluminum alloy ingots. In this paper, the melt flow and solidification structure of Al–4.5Cu alloy were investigated through I-PMS. The grain refinement mechanism of I-PMS is also discussed. The results indicate that the melt flow patterns and distributions can be greatly affected by I-PMS. When I-PMS is applied during solidification, the melt undergoes a series of complicated periodic three-dimensional flows. Compared without I-PMS, the solidification structure of Al–4.5Cu alloy with I-PMS was remarkably refined, and the optimum solidification structure could be realized utilizing appropriate processing parameters.