Ingot casting

Abstract

Disclosed is a mold structure for casting large metallic parts such as ingots so as to avoid the formation of the "shrinkage pipe" which normally develops on the exposed top surface of such castings during their solidification. The structure comprises a cap for placement on a mold which includes a diaphragm having a front surface located to intercept radiation emitted from the top surface of the cooling metal mass and to reemit radiation back thereto, and a means for returning radiation emitted from the back surface of the diaphragm such as an infrared reflector or a stack of baffles. The cap may include means for cooling the reflective surface and suitable ports which allow the interior of the mold and cap to be evacuated. Portions of the mold adjacent its open top may be provided with insulation to prevent heat loss from the metal by conduction. Various means for providing make-up heat to the top surface of the metal mass may also be included in the structure.

Dependencies are inferred from the claim text.