Directional solidification of a metal
AssigneeInductotherm Corp.
InventorsOleg S. Fishman, Joseph T. Belsh, Bernard M. Raffner, Prabhu N. Satyen
Life of this patent
Estimating the term…
Abstract
A molten material can be heated, melted and directly solidified in a single vessel. Induction heating and melting of the molten material is achieved by magnetically coupling the field produced by current flow in a plurality of induction coils surrounding the vessel with either the molten material in the vessel, or a susceptor surrounding molten material in the vessel. Current flow is selectively removed from the plurality of induction coils, and a cooling medium surrounding the vessel, such as water flowing through hollow induction coils, solidifies the molten metal into a highly purified crystalline solid.
Claims22
An apparatus for directional solidification of a metal comprising:
- a vessel for containing a molten mass of the metal;
- a plurality of induction coils surrounding the height of the exterior of the vessel;
- a switching means for each of the plurality of induction coils, each of the switching means having a first switch terminal and a second switch terminal, each of the first switch terminals exclusively connected to a first coil terminal of each of the plurality of induction coils;
- a single source of ac current having a first source terminal and a second source terminal, the first source terminal connected to all of the second switch terminals, the second source terminal connected to all of the second coil terminals;
- and
- a control means for selectively opening and closing each of the switching means to progressively decrease the induced heat from the bottom to the top of the molten mass of the metal in the vessel.
A method of directional solidification of a molten mass of a metal comprising the steps of:
- placing the molten mass of the metal in a vessel surrounded with a plurality of inductions coils connected to a single ac power source;
- selectively switching an ac current to each of the plurality of induction coils from the single ac power source to heat the molten mass of the metal in the vessel;
- and
- progressively decreasing the applied heat by induction from the bottom to the top of the molten mass of the metal in the vessel to solidify the molten mass in the vessel from the bottom to the top of the vessel.
An apparatus for directional solidification of a metal comprising:
- a susceptor vessel for containing a molten mass of the metal;
- a plurality of induction coils surrounding the height of the exterior of the susceptor vessel;
- a switching means for each of the plurality of induction coils, each of the switching means having a first switch terminal and a second switch terminal, each of the first switch terminals exclusively connected to a first coil terminal of each of the plurality of induction coils;
- a single source of ac current having a first source terminal and a second source terminal, the first source terminal connected to all of the second switch terminals, the second source terminal connected to all of the second coil terminals;
- and
- a control means for selectively opening and closing each of the switching means to progressively decrease the induced heat from the bottom to the top of the molten mass of the metal in the vessel.
A method of directional solidification of a molten mass of a metal comprising the steps of:
- placing the molten mass of the metal in a susceptor vessel surrounded with a plurality of inductions coils connected to a single ac power source;
- selectively switching an ac current to each of the plurality of induction coils from the single ac power source to heat the susceptor vessel to heat by conduction and radiation the molten mass of the metal in the susceptor vessel;
- and
- progressively decreasing the applied heat by induction from the bottom to the top of the susceptor vessel to solidify the molten mass in the susceptor vessel from the bottom to the top of the vessel.
Dependencies are inferred from the claim text.