Production of High Purity Magnesium Alloys by Melt Purification with Zr

Abstract

The efficacy of Zr in removing Fe from molten Mg-X binary alloys was studied experimentally and using calculated phase diagrams. Zr is effective in reducing the Fe content from the Mg melt for Mg-X binary alloys, X = Y, Si, Sn, Ca, Sr, Ce, Gd, Nd, Li, La, Mn, and Zn. Purification occurs by the precipitation from the melt of Fe rich precipitates, and the settling of the precipitates to the bottom of the melt. Any desired Fe content down to 1 ppm can be achieved by appropriate melt treatment.

Zr can remove Fe from molten Mg alloys to any desired Fe content down to 1 ppm by appropriate melt treatment. Purification occurs by the precipitation from the melt of Fe rich precipitates, and the settling of the precipitates to the bottom of the melt.