Abstract
This study evaluated the pressure behavior of both the casting chamber and the cavity in the mold using an enclosed one-chamber casting unit. An experimental device with a pressure sensor modeled on the casting system was attached to the casting unit. The chamber pressure rose rapidly and reached half of the preset casting pressure within 0.2s after introducing argon gas into the chamber. Both the preset casting pressure and the gas permeability in the mold strongly influenced the differential pressure between the chamber and the cavity. When a mold with a high level of rising pressure in the cavity, i.e.a mold with higher gas permeability, was used, a large quantity of argon gas penetrated the cavity through the mold wall before the cavity was filled by the molten metal. For this reason, it was thought that some casting defects, such as incomplete casting or gas inclusion, often occur. This study showed that it is desirable to use a mold with lower gas permeability in an enclosed one-chamber casting unit.
