Effect of Vacuum Strength on Product Quality in High Pressure Die Casting Process of Dilute Eutectic Casting Aluminum Alloy

High Pressure Die Casting (HPDC) is, recently, the most widely used industrial casting technology for producing lightweight structural vehicle parts using Al casting alloys. The HPDC process is a complex multiphysics problem that is significantly affected by even minor changes in the process parameters such as shot profiles for metal injection, metal, and die temperatures. In most cases, the HPDC process is assisted with vacuum to evacuate the die cavity ahead of the melt front during liquid metal injection. The vacuum strength during the casting process significantly affects the amount of air entrained within the casting. The entrained air porosity percentage of castings impacts the part quality, mechanical properties, and performance of the component. Experimental trials have been conducted at varying vacuum levels in a 1200-ton Buhler HPDC machine on a plate casting geometry. In tandem, a number of numerical simulations have been carried out using the Flow3D-Cast software with different vacuum strengths, as well. The results of porosity distribution in the simulations matched the locations of deteriorated mechanical properties (% elongation) of samples from the plate casting experiments. The quantified effects of vacuum strength on the elongation percentage of the castings are presented herein for the novel dilute eutectic casting aluminum (DECA) structural alloy of Al-1.1Fe-4.7Zn-1Mg-0.05Ti composition called Nemalloy HE700.