Investment casting method and apparatus, and cast article produced thereby

摘要

Method and apparatus for producing an investment casting from molten material by filling a cavity in a mold with the molten material utilizing at least one porous member in the inlet conduit system of the mold, the porous member enabling evacuation of the mold cavity, through the inlet conduit system and the porous member, and having a structure including pores small enough subsequently to support the molten material upon the porous member by surface tension, with the molten material closing off essentially all atmospheric communication between the inside and the outside of the mold cavity, to thereby prevent passage of the molten material into the mold cavity until the method and apparatus subsequently raises the pressure outside the mold to provide a higher pressure outside the mold cavity and create a differential pressure between the inside and the outside of the mold cavity sufficient to overcome the surface tension and urge the molten material to pass through the pores of the porous member and fill the mold cavity for subsequent cooling and solidification to complete the casting.