Effect of Y addition on removal of Fe impurity from magnesium alloys

The effect of Y addition on Fe-removal effect in magnesium melt was investigated using pure magnesium with a high level of Fe impurity. It was confirmed that Fe concentration was significantly reduced even at relatively high melting and holding temperatures and even with very small amounts of Y. It was also found that Fe contents of magnesium alloys are proportional to the corrosion rates. Hence, magnesium alloys containing Y, which has the strongest Fe-removal ability, have the lowest corrosion rates. The corrosion rate of Mg-3Al-0.2Y is only 1.4 mm/y, corresponding to 0.6% of that of the Mg-3Al alloy (214.9 mm/y).