采用挤压铸造成形工艺制备 AZ91D 镁合金，研究了不同压力 (40 、80 、120 MPa) 和浇注温度 (650 、690 、730和 770 ℃) 对合金组织与性能的影响，优化出高性能挤压镁合金的工艺参数。 结果表明，相同浇注温度下，随着挤压压力的增大，第二相体积分数呈现略微逐渐减少的趋势，在晶界上出现的共晶组织分布越来越不连续， α-Mg 相晶粒尺寸逐渐减小；相同挤压压力下，合金的晶粒尺寸随着浇注温度的升高逐渐长大。 在 730 ℃ 浇注温度、 80 MPa 挤压压力下获得的挤压铸件综合力学性能最好，其致密度达到最高，为 99.78％ ，较原材料提高 1.4％ ；抗拉强度由 121.2 MPa 提高到 219.5 MPa ，提高了 81.1% ；伸长率由 1.6% 提高到 6.4% ，提高了 300% 。

The effects of different pressures and pouring temperatures on the microstructure and properties of AZ91D magnesium alloy prepared by squeeze casting technology were studied, and better process parameters were explored to provide guidance for the production of high-quality magnesium alloy castings. The results show that at the same pouring temperature, with increasing extrusion pressure, the volume fraction of the second phase presents a slightly decreasing trend, the eutectic structure distribution on the grain boundary becomes increasingly discontinuous, and the α-Mg phase decreases gradually. At the same extrusion pressure, the grain size of the alloy gradually grows with increasing pouring temperature. The comprehensive mechanical properties of extrusion casting obtained at 730 ℃ pouring temperature and 80 MPa extrusion pressure are the best, with the density reaching the highest value of 99.78%, which is 1.4% higher than that of the raw materials. The tensile strength increases by 81.1% from 121.2 MPa to 219.5 MPa, and the elongation increased by 300% from 1.6% to 6.4%.