Numerical Simulation of Fluid Flow, Solidification and Casting Defects of a Gas Control Valve Produced by High-Pressure Die Casting

Numerical process simulation has become a key tool for designing the geometry of metal castings and optimizing process parameters. Its integration is replacing traditional casting approaches, which are often still based on trial and error, thereby supporting a more robust component design phase. This approach aims to streamline die development and mitigate component defectiveness by identifying potential issues before the start of mass production. This work studied the fluid flow during the filling phase of a gas control valve produced with an AlSi12Cu1(Fe) alloy by high-pressure die casting using commercial FLOW-3D^® simulation software. The accuracy of the filling simulation was assessed by conducting experimental interrupted filling tests. Furthermore, the thermal management of the die was studied via numerical simulation and experimentally validated using infrared thermography, which provides real-time surface temperature maps during production. By linking thermal gradients recorded by the infrared camera with the occurrence of shrinkage porosity, a deeper understanding of the correlation between die cooling efficiency and part quality was achieved. The study then focused on the solidification process, with a specific emphasis on identifying solidification-related defects. Computed X-ray tomography (CT) was employed to evaluate the amount and distribution of internal porosity throughout the component. The results were compared against the quality criteria integrated into the simulation software, which are based on both a pressure drop model during solidification and a two-phase model considering air compressibility and surface tension. The high-resolution CT scans provided a non-destructive means to quantify internal porosity, allowing for a rigorous validation of the simulation’s predictive capabilities regarding defect location. The numerical results showed good agreement with experimental data, demonstrating the benefits linked to the exploitation of simulation tools.