A series of experiments were carried on aluminum alloy die casting using Al-8 mass % Si and Al-11 mass % Si alloy. The study is especially focused on clarifying the relation between the gate size and casting sproperty. Die casting when the gate thickness is changed from 1 to 4 mm, shows that cavity is filled completely with the melt at 4mm thickness and for a wide melt superheat range, whereas the filling condition becomes worse as the gate thickness decreases. Surface quality of the castings also drops with the decrease of the gate thickness. It is observed that the melt is likely to solidify near the gate as its thickness decreases. As the result, solid fraction in the metal increases during the cavity filling for a thin gate, leading to incomplete cavity filling and poor surface quality.
