Hypereutectic Al alloys diecast at semi-solid state

An innovative hypereutectic Al-Si-Cu-Fe foundry alloy with 14.4 wt.% Si and 1.6 wt.% Fe has been investigated, as well as the production process. The process used to produce the castings exploits the Rapid Slurry Forming (RSFTM) technology in comparison with the traditional High-Pressure Die-Casting (HPDC) process. The experimental activity has been carried out at different pouring temperatures and plunger velocities during the filling phase, with the aim to evaluate the correlation between production parameters, alloy composition, microstructure and mechanical properties. Higher the plunger velocity and lower the pouring temperature, better the casting properties. High plunger velocities mainly avoid cold shuts formation, while intermediate pouring temperatures, by increasing the material viscosity, prevent turbulence and gas entrapment