Significance of gate geometry and injection speed on the flow behaviors of molten Al alloy during die filling

The effects of injection speed and gate geometry on the flow behaviors of molten Al alloy (Newtonian fluid) were investigated by direct observations of the flow patterns during die filling. High-speed photography was employed to record the real time flow patterns of the molten metal during the die filling sequence. Qualitative assessments of the critical gate speed were made based on the experimental results. The experimental results were also compared with results predicted based on the Reynolds number. Although the critical gate speed varies depending on the gate geometry, a gate speed of ∼0.5 m/s is considered optimal to control the flow behavior of the melt in a planar flow during die filling.