Thermodynamic Calculation of the Liquidus Projections of the Al-Cu-Fe-Mg, Al-Cu-Mg-Si, and Al-Fe-Mg-Si Quaternary Systems on Al-Rich Corner

The thermodynamic calculations of Al-Cu-Fe-Mg, Al-Cu-Mg-Si and Al–Fe–Mg–Si quaternary systems were carried out using CALPHAD method, based on the Al–Cu–Fe–Mg–Si thermodynamic database. The liquidus projection of Al–Cu–Fe–Mg, Al–Cu–Mg–Si and Al–Fe–Mg–Si quaternary systems at Al-rich corner were constructed, and the solidification structures of Al-12Cu-7Mg-1Fe, Al-14Cu-2Mg-4Si, Al-0.3Fe-6Mg-12Si (wt.%) alloys were analyzed by the Scheil solidification simulation. The calculated results agree well with the previous experimental data. The liquidus projections of three quaternary aluminum alloys at the Al-rich corner were accurately plotted, which could be helpful for the analysis of solidification process of multicomponent alloy systems, and provide an important theoretical basis for the material design of aluminum alloys.

Thermodynamic Calculation of the Liquidus Projections of the Al-Cu-Fe-Si and Al-Cu-Fe-Mg-Si Multicomponent Systems on Al-Rich Side

The thermodynamic calculations of Al–Cu–Fe–Si quaternary system and Al–Cu–Fe–Mg–Si quinary system were carried out using CALPHAD approach based on the Al–Cu–Fe–Mg–Si thermodynamic database. The liquidus surface projection of Al–Cu–Fe–Si quaternary system at the Al-rich corner was constructed, and then the solidification structures of four Al–Cu–Fe–Si alloys were analyzed by the Gulliver-Scheil solidification simulation. The calculated results were in good agreement with the previous experimental data. The liquidus surface projections of A1–Cu–Fe–Mg–Si quinary system at the region of Al-Cu, Al-Si and Al-Mg were constructed, respectively. The liquidus projection of the multicomponent aluminum alloy system at the Al-rich side was accurately drawn, which could accurately predict the primary phase in the solidification process of the alloy. This work has an important guiding significance for the design of the aluminum alloys.

Recent Developments of Rheo-Diecast Components for Transportation Markets

Recent developments and applications of rheo-diecast components for transportation markets are described. The components have been produced using the SEED (Swirled Enthalpy Equilibrium Device) semi-solid process. The development process typically involves several steps, including (1) an evaluation (and modification) of the component design to ensure it is suitable for semi-solid die casting, (2) the use of flow and solidification simulation to optimize the layout of the gating system, and to ensure that the modified component design can be produced without filling turbulence and shrinkage porosity, (3) stress modeling to ensure that the redesigned component will meet performance targets, and (4) in-plant development of the optimum process parameters. This development process will be described in detail for several commercial components, including two brackets for trucking applications, and connectors used in the frame of an electric bus.