Grain refinement of solidified Mg–Al alloys by limited angular oscillation

Abstract

By introducing limited angular oscillation (LAO) during the initial stages of solidification, experiments were conducted to examine the potency of LAO for grain refining of commercial Mg–Al alloys. Significant grain refinement has been successfully achieved at oscillation intensities above the critical value. The refinement effect by solute content occurs across the oscillation intensity range examined and is more pronounced under the conditions of weak oscillation intensity. The refinement effectiveness for Mg–Al alloys is AZ31>AZ61>AZ91. Oscillation intensity plays a more important role in determining the extent of grain refining than the solute content. Theoretical discussions provide new clues to understanding of the mechanism of grain refinement by LAO.