Effect of Flow State of Pure Aluminum and A380 Alloy on Porosity of High Pressure Die Castings

Abstract

Air entrapment defects prevent the heat treatment from improving the mechanical properties of die castings, which limits the die casting of high-performance components. The flow pattern of the filling process is complicated and experimental analysis is difficult in thin-walled complex die castings. In this study, we constructed a shock absorption tower to observe in real-time the filling process of pure aluminum and A380 aluminum alloy at different fast injection speeds. The degree of breakup of pure aluminum was larger than that of A380 during the filling process, which caused the porosity of pure aluminum to be greater than that of the A380 at each observation position. Re-Oh diagrams explained the difference in porosity between the two metals. The porosity in different regions was closely related to the flow state of aluminum liquid. In addition to porosity measurements, we specifically analyzed the relationship between the porosity of the flowback zone, the final filling zone, and the near-tail zone of cylinder. At the same injection velocity, the porosity at flowback zone was greater than that at the final filling position, the porosity at final filling position was larger than that at the near-tail zone of cylinder, and the final filling position changed as the injection velocity changed.

Mechanical Properties of a Structural Component Processed in High-Pressure Die Casting (HPDC) with a Non-Heat-Treated Aluminum Alloy

“…HPDC parts for structural and non-structural products and applications are gradually replacing steel-based components within the vehicle structure; these hybrid body structural vehicles are becoming one of the most effective solutions to achieve lightweighting [14]. Another benefit of this process is that it has great dimensional accuracy and shape precision [15], particularly for complex components with thin-wall thickness.…”

Minimizing the Casting Defects in High Pressure Die Casting Using Taguchi Analysis

“…The 1 st stage plunger velocity is linked with the filling of die casting chamber in machine, whereas the 2 nd stage plunger velocity is correlated with filling of the die cavity [19]. Air entrapment defects occur normally during the heat treatment process due to variations in the cooling temperature while dealing with the A380 alloy [20]. The solidification behavior during filling has a very significant effect on surface defects.…”