Effect of AC magnetic field on solidified structure and mechanical properties of Mg_(97)Y_2Cu_1 alloy

摘要

The influences of different voltage and mold temperature on solidified structure and mechanical properties of Mg_(97)Y_2Cu_1 alloy reinforced by long-period ordered structure under AC magnetic field were studied. The results show that grains of Mg_(97)Y_2Cu_1 alloy can be refined by AC magnetic field treatment. Macrostructure of the alloy is changed from coarsened grains to complete fine equiaxed grains. The initial dendrites are broken and and they have a tendency to break into several fragments. The second phase becomes more continuous and uniform, its volume fraction increases. When the voltage is at 0-250V, grain size of the alloy decreases firstly, then increases, and the turning point is 200V. When the mold temperature is at 20-600°C, grain size of the alloy increases grossly with the increase of the mold temperature. The change law of mechanical properties of the alloy is opposite to the change law of grain size. When the voltage is 200 V, the tensile strength and elongation of the alloy are increased by up to 16% and 47%, respectively, compared with the alloy in traditional condition.