Investment casting with improved melt filling
AssigneeHowmet Research Corporation
InventorsMark L. Soderstrom, Bart M. Kilinski, John R. Brinegar, Brad J. Murphy
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Abstract
Molten metallic material is cast into a mold that is made with a barrier to reduce gas permeability through a mold wall that forms on its innermost side a mold surface for contacting the molten metallic material. The molten metallic material is gravity cast into the mold residing in a furnace in a casting chamber under a first pressure, such as subambient pressure. Then, a gaseous pressure is provided in the casting chamber higher than the first pressure rapidly enough to reduce or eliminate the presence of localized voids in the casting solidified in the mold.
Claims13
A method of casting a molten metallic material, comprising providing a mold having a mold wall for contacting the molten metal, said mold wall including a refractory barrier to gas permeability effective to delay gas pressure equalization between an exterior and interior of said mold wall, introducing the molten metallic material into said mold under a first pressure and then applying gaseous pressure higher than said first pressure to said material in the mold.
A method of investment casting a molten metallic material, comprising providing a shell mold having a mold wall forming a mold surface of a mold cavity for contacting the molten metal, said mold wall being substantially gas impermeable, introducing the molten metallic material into said mold in a casting chamber under a first pressure by flowing said material by gravity from a pour cup through a passage to said mold cavity to fill said mold cavity, and then providing in said chamber a gaseous pressure higher than said first pressure.
Dependencies are inferred from the claim text.