针对汽车镁合金转向器铸件,采用数值模拟的方法研究了其真空压铸成形过程,分析了在高真空度条件下金属液充型的特点,并在此基础上对比研究了在高真空度、低真空度以及常压条件下充型及凝固的规律。结果表明,提高型腔真空度能有效地提高金属液充型能力,避免铸件内气孔的产生,但对缩孔、缩松缺陷的形成没有影响。 In view of the automotive magnesium alloy steering castings, the process of vacuum die casting was studied by means of numerical simulation. The characteristics of filling of molten metal under high vacuum degree were analyzed. On the basis of this, Vacuum and filling conditions under atmospheric conditions and the law of solidification. The results show that increasing the cavity vacuum can effectively improve the chargeability of the molten metal and prevent the formation of pores in the castings, but has no effect on the formation of shrinkage cavities and shrinkage defects.