Effect of Ca on Al-Mg Alloy

Abstract

Oxidation of Mg in molten Al-Mg alloys is prevented by the addition of 0.5-0.05% Ca. This effect is most remakable when the Mg content in the alloy is as high as 5-10%.
As the melting is repeated, the effect gets reduced. But when the quantity of Ca added is appropriate, the effect is kept remained up to the third melting. Gas content of the alloy of this system is reduced by the addition of Ca. This effect is better than in the case of adding Be.
As to the castablity, however, the addition of Ca is less effective than the addition of Be. But when the Mg content of this type alloy is about 10%, the effective of the addition of Ca is as same as that of the addition of Be.