An apparatus has been built to study the grain refining effect of mechanical vibrations applied during the solidification of magnesium alloys. The experimental setup consists of a pneumatic vibrator attached to a vertical beam onto which a permanent mold is clamped. This mold experiences peak accelerations up to 120 m/s~(2) at a frequency of 160 Hz and an amplitude of 0.12 mm. This method of transferring the vibrational energy to the molten metal is surprisingly efficient as less than 55 W are needed to maintain the resonant oscillatory motion. It is shown that vibrations are severe enough to induce grain refinement in high-purity magnesium and in a commercial purity AZ91 magnesium alloy.
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