Low-cost binary wrought magnesium alloy with excellent mechanical properties and preparation method thereof

The invention discloses a low-cost binary wrought magnesium alloy with excellent mechanical properties. The low-cost binary wrought magnesium alloy comprises the following components in percentage by mass: 0.5-5% of Dy and the balance of magnesium and inevitable impurities, the preparation method comprises the following steps: weighing the raw materials of the binary wrought magnesium alloy according to the proportion, then smelting and casting to obtain a cast ingot, and sequentially carrying out solid solution and hot extrusion treatment on the cast ingot; the solution treatment is carried out under the condition of air isolation, the temperature is 400-550 DEG C, the heat preservation time is 12-36 hours, and then water cooling is carried out; the temperature of the hot extrusion treatment is 250-450 DEG C, the extrusion ratio is (10: 1)-(80: 1), and the extrusion speed is 0.5-3m/min. The Dy element is added to generate an obvious grain refinement effect, and the strength and/or plasticity of the alloy can