Clean melt nucleated casting systems and methods with cooling of the casting

A casting system for producing a metal casting from an ingot including defects and any one of oxides, sulfides, contaminants, and other impurities, the metal casting comprising a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification of the metal from a semi-solid state to a solid state, the casting system comprising:

• a source of liquid metal formed from the ingot including defects and any one of oxides, sulfides, contaminants, and other impurities and essentially free of the oxides and sulfides that originate in the ingot;
• a metal disruption site through which a stream of the liquid metal is formed into molten metal droplets;
• a cooling zone that receives the molten metal droplets, the molten metal droplets being solidified in the cooling zone into semisolid droplets such that, on average, about 5% to about 40% by volume of each semisolid droplet is solid and the remainder of the semisolid droplet is molten;
• a mold that collects the droplets in a semi-solid portion and solidifies the droplets thereby forming an article having a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free and segregation defect free, and essentially free of voids caused by air entrapped during solidification of the metal from a semi-solid state to a solid state, and
• a cooling system that supplies coolant in the form of a spray directly to the casting through at least one aperture disposed in the mold to cool the metal casting in a manner sufficient to cool a semi-solid portion of the metal casting, wherein the metal casting is cooled in a manner sufficient to provide a microstructure that comprises a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification from a semi-solid state to a solid state.

A casting method for forming a metal casting from an ingot including defects and any one of oxides, sulfides, contaminants, and other impurities, the metal casting comprising a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification of the metal from a semi-solid state to a solid state, the method comprising:

• forming a source of clean refined metal from the ingot including defects and any one of oxides, sulfides, contaminants, and other impurities that has oxides and sulfides refined out by electroslag refining;
• forming the article by nucleated casting into a mold;
• and
• cooling a semi-solid portion of the metal casting by supplying coolant in the form of a spray directly to the casting through at least one aperture disposed in the mold, wherein the step of cooling is sufficient to cool the metal casting in a manner sufficient to provide a microstructure that comprises a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification from a semi-solid state to a solid state.

A casting method for forming a metal casting from an ingot including defects and any one of oxides, sulfides, contaminants, and other impurities, the metal casting comprising a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification of the metal from a semi-solid state to a solid state, the method comprising:

• forming a source of clean refined metal from the ingot including defects and any one of oxides, sulfides, contaminants, and other impurities that has oxides and sulfides essentially refined out by electroslag refining;
• forming the article by nucleated casting into a mold;
• and
• cooling a semi-solid portion of the metal casting by providing a cooling system that comprises a coolant supply and a coolant conduit, the step of supplying comprises applying coolant from the coolant supply in the form of a spray directly to the casting through at least one aperture disposed in the mold, wherein the step of cooling is sufficient to cool the metal casting in a manner sufficient to provide a microstructure that comprises a fine-grain, homogeneous microstructure that is essentially oxide- and sulfide-free, segregation defect free, and essentially free of voids caused by air entrapped during solidification from a semi-solid state to a solid state.