VACUUM DIE CASTING MACHINE AND PROCESS

摘要

A vacuum die and process for casting alloys includes a cold chamber having a bore and molten alloy inlet. A vacuum chamber encloses the cold chamber to provide a vacuum at the inlet. A plunger rod has a plunger tip which seals the bore and moves for forcing molten metal into a die cavity. The plunger tip in one embodiment has a first section facing the die cavity for sealing to the bore and a second reduced diameter section remote from the die cavity. In other embodiments, the plunger tip includes a sealing ring, the sections are reversed, or an inert gas floods the tip area. A vacuum source is coupled to the die cavity and is selectively coupled to the vacuum chamber through the molten alloy inlet of the cold chamber when the plunger tip moves to a side of the inlet remote from the die.