通过对比试验研究了铸造方法对ZL205A合金的砂型铸态组织的影响。结果表明,对于低压铸造,由于合金在压力下凝固,相对于重力铸造,晶粒尺寸得到不同程度的细化,铸件显微缩松明显减少,致密度显著提高。此外,通过试验也可看出,铸态合金晶粒对激冷作用敏感,冷却速率大,铸态晶粒细小。对于常规铸件,由于凝固后期冷却速率较慢,α-Al基体中有θ-Al2Cu相呈片状析出,因而,对ZL205A合金铸件强度有影响。 The effect of casting method on the as-cast microstructure of ZL205A alloy was studied through comparative experiments. The results show that for low pressure die casting, the grain size is refined to some extent due to the solidification of the alloy under pressure, compared with gravity casting. The micro-shrinkage of the castings is obviously reduced and the density is significantly increased. In addition, the experiment also shows that the as-cast alloy grains are sensitive to the chilling effect, the cooling rate is large, and the as-cast grains are small. For the conventional castings, due to the slow cooling rate in the late stage of solidification, the θ-Al2Cu phase precipitates in the α-Al matrix, and therefore affects the strength of the ZL205A alloy castings.