Method for casting thin metal objects
View Patent ↗Provided herein are various embodiments of systems for casting thin metal plates and sheets. Typical embodiments include layers of mold cavities that are oriented vertically for casting the metal plates. In some embodiments, the mold cavities include a beveled edge such that the plates that are cast have a beveled edge. In some embodiments, the mold cavities are filled with a molten metal through an open horizontal edge of the cavity. In some embodiments, the mold cavities are filled through one or more vertical feed orifices. Further disclosed are methods for forming a thin cast metal plate or sheet where the thickness of the cast part is in a range from 0.005 inches to 0.2 inches, and the surface area of the cast part is in a range from 16 square inches to 144 square inches.
1. A method of forming a cast metal sheet comprising:
melting a solid metal having a melting temperature to form a molten metal;
preheating a mold having a cavity to a first temperature greater than the melting temperature of the metal;
flowing the molten metal into the cavity;
cooling the molten metal to a second temperature below the melting temperature of the metal to form the cast metal sheet; and
removing the cast metal sheet from the mold,
wherein a distributor is removably attached to the mold, a distributor cap is removeably attached to the distributor for providing thermal conductivity between a crucible and the mold, and the crucible is removeably attached to the distributor cap, and
wherein the solid metal is formed into a molten metal in the crucible disposed above the mold and the molten metal is flowed into the cavity from the crucible through the distributor having at least one funnel-shaped orifice.
2. The method of claim 1 wherein the mold includes a plurality of cavities and the molten metal is flowed into the plurality of cavities from the crucible.
3. The method of claim 1 wherein the cavity has a thickness less than about 0.020 inches and a thickness-to-surface ratio less than about 0.00125 in./sq. in.
4. The method of claim 1 further comprising maintaining the mold with the molten metal in the cavity at the first temperature above the melting temperature of the metal for at least one minute prior to cooling the molten metal to the second temperature below the melting temperature of the metal.
5. The method of claim 1 wherein preheating the mold to the first temperature greater than the melting temperature of the metal comprises preheating the mold to at least 100° C. greater than the melting temperature of the metal.
6. A method of forming a cast metal sheet comprising:
melting a solid metal having a melting temperature to form a molten metal;
forming a cavity in a mold by joining a plurality of casting surfaces, the plurality of casting surfaces including:
a mold backing structure having a mold backing structure plate that forms a mold cavity first planar surface and having a mold cavity first framing portion that forms a mold backing structure first surface and a mold cavity first edge portion, and
a mold facing structure having a mold cavity second planar surface, wherein the mold backing structure first surface is removably attachable to the mold cavity second planar surface,
the combination of the mold cavity first planar surface, the mold cavity second planar surface, and the mold cavity first edge portion forming the cavity and a first open edge for providing a flow of a molten metal into the cavity;
preheating the mold having the cavity to a first temperature greater than the melting temperature of the metal;
flowing the molten metal into the cavity;
cooling the molten metal to a second temperature below the melting temperature of the metal to form the cast metal sheet; and
removing the cast metal sheet from the mold,
wherein a distributor is removably attached to the mold backing structure and the mold facing structure, a distributor cap is removeably attached to the distributor for providing thermal conductivity between a crucible and the mold, and the crucible is removeably attached to the distributor cap, and
wherein the solid metal is formed into a molten metal in the crucible disposed above the mold and the molten metal is flowed into the cavity from the crucible through the distributor having at least one funnel-shaped orifice.
7. The method of claim 6 further comprising treating the casting surfaces with a mold release material prior to forming the cavity.
8. The method of claim 6 wherein the mold includes a plurality of cavities and the molten metal is flowed into the plurality of cavities from the crucible.
9. The method of claim 6 wherein the cavity has a thickness less than about 0.020 inches and a thickness-to-surface ratio less than about 0.00125 in./sq. in.
10. The method of claim 6 further comprising maintaining the mold with the molten metal in the cavity at the first temperature above the melting temperature of the metal for at least one minute prior to cooling the molten metal to the second temperature below the melting temperature of the metal.
11. The method of claim 6 wherein preheating the mold to the first temperature greater than the melting temperature of the metal comprises preheating the mold to at least 100° C. greater than the melting temperature of the metal.