Available methods for grain refinement of cast ingots have been reviewed and mechanisms have been discussed. Based on this a strategy for efficient grain refinement of commercial wrought Alalloys is presented. Although techniques like ultrasonic treatment and electromagnetic stirring have been developed, grain refinement using inoculants through the addition of AlTiB rod and AlTi waffles is still recommended for most industrial applications. Two criteria need to be fulfilled for efficient number of potential nuclei (TiB_2 particles through rod addition) must be present and a large fraction of the potential nuclei must be activated (determined by growth restriction and constitutional undercooling).
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