Study on mechanical properties of Mg–Al–Zn–Mn alloys cast by two different methods

The mechanical properties of Mg–Al–Zn–Mn alloys cast by gravity die and vacuum suction methods were investigated. The results of orthogonal test indicate that Al has the most significant effect on the mechanical properties of Mg–Al–Zn–Mn alloys, but Al act differently by different casting methods. Compared these samples produced by vacuum suction casting with those by gravity die casting, the mechanical properties of samples by gravity die casting are higher. The reason is that under the condition of high cooling rate and metal fluid erosion the grain size of samples by gravity die casting is smaller than that of samples by vacuum suction casting. The average grain size of magnesium alloy samples by gravity die casting is about 75 μm and that by vacuum suction casting is about 120 μm.