Patent ID: 8347949

Claim:
A method of fully or partially eliminating a shrinkage cavity in a metal ingot cast by direct chill casting, the method comprising: casting a metal ingot by introducing molten metal into a direct chill casting mold from a spout to form an upright ingot having an upper surface at a predetermined height; upon completion of said casting, terminating molten metal flow through the spout while maintaining sufficient heat in metal within and supplying the spout to keep the metal molten for subsequent delivery through the spout; allowing a partial shrinkage cavity to form in said upper surface as metal of the ingot contracts, then at least partially filling said partial shrinkage cavity while avoiding all or significant spillage of molten metal from the partial cavity, and then terminating flow of metal through said spout; repeating at least once said steps of allowing a partial shrinkage cavity to form in said upper surface, then at least partially filling said partial shrinkage cavity with molten metal from said spout, and then terminating the flow of metal through the spout; terminating said repetition of said steps; and removing said spout from contact with molten metal of said ingot and allowing all parts of said ingot to cool to a temperature at which the metal is fully solid.