Production of high purity magnesium from Mg-Al-Ca system alloy by vacuum distillation and corrosion resistance and tensile properties of its extrusions

In order to improve the property of high purity magnesium produced from Mg-Al-Ca alloy, vacuum distillation and extrusion method has been employed. The vacuum distillation with the raw material temperature of 600°C, condenser temperature of 310-350°C, and purification time at 8 h is able to control the amount of impurity such as Fe, Ni and Cu less than 0.0003%. The efficiency of purification and condenser condensate of alloy is achieved nearly 90%. The corrosion rate of high purity magnesium after extruded at 300-375°C and extrusion ratio of 100 is about 0.4 mm/y, which is better than that of purity 99.99% magnesium. Further, the tensile strength of extruded specimen is about 200 MPa, and the elongation is about 15%.