Abstract: A foamed pattern of a desired part is first formed. The pattern is then dipped into a ceramic slurry and the slurry dried in order to form a shell containing the foamed pattern. A heated bed of a particulate medium is formed around the ceramic shell which causes the pattern to evaporate and form a mold. A molten metal is then introduced into the mold and solidified while being held at an elevated temperature for a period of time to accomplish a desired heat treatment of the metal. With this method, the casting does not have to be subsequently heat treated in a separate operation. It can be removed as an as cast casting, having the desired microstructures.

Abstract: A method is disclosed for the casting of metals by the use of a consumable or vaporizable pattern. In this method, a foamed pattern of a desired part is first formed. The pattern is then dipped into a ceramic slurry and the slurry dried in order to form a shell containing the foamed pattern. A bed of a particulate medium heated to a temperature of from 700.degree. to 1000.degree. F. is formed around the ceramic shell to cause the pattern to vaporize without burning and form a mold. A molten metal is then introduced into the mold, solidified and removed from the mold to form a casting. An inert atmosphere can be provided over the bed of heated particulate medium during the vaporization of the pattern to help suppress the burning of the vaporized pattern.

Abstract: A method is disclosed for the casting of metals by the use of a consumable or evaporative pattern. In this method, a foamed pattern of a desired part is first formed. The pattern is then dipped into a ceramic slurry and the slurry dried in order to form a shell containing the foamed pattern. A heated bed of a particulate medium is formed around the ceramic shell which causes the pattern to evaporate and form a mold. A molten metal is then introduced into the mold, solidified and removed from the mold to form a casting.