Apparatus for casting low-density alloys

摘要

Apparatus for casting of low-density metals, such as magnesium alloys, into an air-permeable mold includes a housing forming a substantially airtight chamber in which is disposed a mold assembly including a mold secured between top and bottom plates by encircling bands or straps. A bottom-discharge reservoir vessel for molten metal is disposed above the mold, the vessel outlet communicating with the mold inlet through a coupling against which the mold assembly is resiliently urged by bias springs to insure an airtight coupling. A valve is selectively operable for opening and closing the vessel outlet and closure apparatus cooperates with the vessel for providing a substantially airtight closure thereof. A pressure control system is coupled to the vessel and the chamber for establishing a pressure differential therebetween which cooperates with gravity to urge the molten metal from the vessel into the mold when the valve is open. In one embodiment the vessel is disposed within a separate airtight chamber above the mold chamber, and in another embodiment the vessel is closed by an airtight cover plate. Clamps are provided for opening and closing the vessel and chambers to provide access to the interiors thereof.