Recycling from Mg-Al-Zn system alloy to the high-purity Mg-Zn alloy by the vacuum distillation method

Machined chips of the Mg-Al-Zn alloy were converted to a raw material, and the recycling from Mg-Al-Zn system alloys to high-purity Mg-Zn alloys by the vacuum distillation method was examined. For 100 g of raw material AZ31 magnesium base alloy machined chips, a raw material temperature of 600°C, a condenser temperature of 355°C, and a purification time 7 h, the evaporation ratio is nearly 95%. The condenser condensate becomes about 93%, and Mg and Zn in the raw material can be almost completely recovered in the condenser as high purity Mg-Zn alloy that is free of impurities such as Fe, Ni and Cu. The corrosion rate of recycling extrusions became a little worse in comparison with about 0.5mm/y for 4 N magnesium extrusion samples, and the corrosion resistance became better than that of AZ91D magnesium base alloy die castings. The recycling extrusions was elongated a little less in comparison with the 4 N magnesium extrusions, and the tensile strength and the 0.2% proof stress increased to about 50 MPa.