Rationality of gating system in the die casting process has great effects on the mechanical properties of the standard casting samples. The Flow-3D software was employed to analyze and optimize the existed gating system of standard samples. Meanwhile

design and optimization of high vacuum die casting for standard samples were conducted. The results show that gas entrapment and liquid alloy backflow occurred around the runner nearby the ingate during slow speed filling stage in the existing die casting process. And they could be significantly reduced with the transition angle between the sprue and the runner increasing to 30 mm

while tapered runner with buffer structure was adopted

the backflow and gas entrapment can be moved to the packet buffer

and the liquid metal with gas entrapment can be avoided before moving into cavity

which is beneficial for the improvement of die castings quality. Air vent located in the side of the overflow can effectively eliminate the blockage of exhaust passage among different samples

which ensures adequate exhausting time after the samples are filled completely. Therefore

the internal quality of the castings is improved.