中文摘要：

将石膏型熔模铸造和反重力铸造工艺相结合,在不同充型压力下制备ZM5镁合金,研究了充型压力对镁合金石膏型薄壁件成形能力及合金铸态组织和拉伸性能的影响,得到了最佳的铸造工艺参数。结果表明：随着充型压力增大,铸态镁合金的组织明显细化;当充型压力为40kPa时,铸件的成形能力最好,镁合金的拉伸性能最佳,抗拉强度为（192±5）MPa,伸长率为（1.5±0.2）%;330-350℃的铸型预热温度、730-750℃的浇注温度、35-40kPa的充型压力能够满足镁合金薄壁件浇注的需要。

英文摘要：

ZM5 magnesium alloy was prepared at different filling presures by combining gypsum mould and counter gravity casting process, and the effects of filling pressure on filling ability of thin-wall casting, microstructure and tensile properties of as-cast magnesium alloy were studied. At last, the optimal casting parameters were obtained. The results show that, with the increase of filling pressure, the casting microstructure was obviously refined. The optimal filling pressure with maximum tensile properties was 40 kPa at which the filling ability of the thin-wall casting was better and tensile strength was （192--5） MPa, elongation was （1.5±0.2）%. The casting process with preheating temperature of 330--350 ℃, pouring temperature of 730--750 ℃ and filling pressure of 35-40 kPa can meet the need of thin-wall castings of magnesium alloy.