Patent ID: 7461684

Claim:
A method for producing a cast article comprising the steps of: a) providing a porous powder article having a relative density of less than about 80 percent; b) forming a mold having an article-forming cavity in the shape of the porous powder article by applying a moldable material around the porous powder article so that the porous powder article is the pattern for the article-forming cavity of the mold and the porous powder article fills the entire article-forming cavity; c) pouring a molten metal stream into the article-forming cavity, said molten metal stream extirpating the porous powder article to produce a liquid and/or solid residue, wherein said residue flows with the molten metal stream within the article-forming cavity and the residue-bearing molten metal fills the entire article-forming cavity; and d) solidifying the residue-bearing molten metal in the article-forming cavity to produce a cast article, wherein said cast article is not an infiltrated porous article; wherein, at the start of step (c), the temperature of the mold is lower than the solidus temperature of the molten metal.