真空压铸的型腔气体排气理论分析

Theoretical Analysis of Exhaust in Mold Cavity in Vacuum Die Casting

真空压铸能有效减少铸件内的气孔缺陷,提高铸件的致密度。将型腔内的气体快速排出是真空压铸技术的关键,也直接影响真空压铸件的质量。通过分析气体在真空排气管路中的流动物理过程,研究影响型腔真空度的主要工艺因素,提出使型腔快速达到高真空度的最优化工艺参数方案。结果表明,大截面、短距离的排气通道、大抽气速度,小抽气容积有利于型腔快速达到高真空度。

Density of the die castings was improved as a result of effectively reducing gas hole in the castings through vacuum die casting.It was a key point for rapid exhaust in cavity in vacuum die casting,which directly affected the quality of die castings.Through analyzing flow process of gas in vacuum exhausting pipe,main factors influencing vacuum rate in cavity were investigated,and optimized processing parameters were presented to rapidly realize high vacuum rate in cavity.The results show that it is beneficial for rapid realization of high vacuum rate in cavity by setting exhausting pipe with large section and short distance and high exhausting speed as well as small cavity volume.