Dual vacuum induction melting & casting

Abstract

A furnace system for melting and casting metals, alloys, and superalloys and a related method. A melt chamber of the furnace system is configured and arranged to include at least two melt boxes, thereby increasing the volume of alloy charge that can be rendered molten during a single furnace heating cycle. Accordingly, a number of ceramic casting molds equal to the number of melt boxes can be used to form castings following a single furnace heating cycle. The ceramic casting molds can be pre-heated in an external oven before being introduced to the mold or loading chamber of the furnace system. The throughput of the furnace system is increased by the ability to pour more than one casting per alloy charge melting cycle.

What is claimed is: 
     
         1 . A vacuum induction casting apparatus, comprising:
 a loading chamber, configured to receive a casting mold;   a melt chamber, configured to concurrently house a first melt box and a second melt box;   an interlock mechanically coupled to both the loading chamber and the melt chamber;   a loading mechanism, configured to move the casting mold into and out of the melt chamber through the interlock to a casting position; and   a vacuum system coupled to both the melt chamber and to the loading chamber.   
     
     
         2 . The vacuum induction casting apparatus according to  claim 1 , wherein the loading mechanism is a loading elevator configured to reciprocally move the casting mold vertically through the interlock. 
     
     
         3 . The vacuum induction casting apparatus according to  claim 1 , wherein the loading mechanism is a platen configured to reciprocally move the casting mold horizontally through the interlock. 
     
     
         4 . The vacuum induction casting apparatus according to  claim 1 , further comprising a charge temperature sensor system coupled with the melt chamber and configured to measure temperatures of one or more molten charges in either or both of the first melt box and the second melt box. 
     
     
         5 . The vacuum induction casting apparatus according to  claim 1 , further comprising a mold temperature sensor system coupled with the melt chamber and configured to measure a temperature of a mold within the casting mold. 
     
     
         6 . The vacuum induction casting apparatus according to  claim 1 , wherein the vacuum system separately controls pressure within the melt chamber and the loading chamber. 
     
     
         7 . The vacuum induction casting apparatus according to  claim 1 , wherein the vacuum system further comprises a first vacuum system and a second vacuum system atmospherically separate from each other, wherein the first vacuum system is coupled to the melt chamber and wherein the second vacuum system is coupled to the loading chamber. 
     
     
         8 . The vacuum induction casting apparatus according to  claim 1 , wherein the apparatus is further configured to allow for the melt chamber to load an alloy charge into either or both of the first melt box and the second melt box concurrent with the loading mechanism in a position outside of the melt chamber. 
     
     
         9 . The vacuum induction casting apparatus according to  claim 1 , further comprising a third melt box. 
     
     
         10 . The vacuum induction casting apparatus according to  claim 9 , further comprising a fourth melt box. 
     
     
         11 . A method of forming castings, comprising:
 loading a first alloy charge into a first melt box and a second alloy charge into a second melt box within a melt chamber of a furnace system;   melting the first and second alloy charges within the first melt box and the second melt box to be molten;   pre-heating an initial casting mold and pre-heating a subsequent casting mold;   loading the initial casting mold into a loading chamber of the furnace system;   moving the initial casting mold to a casting position within the melt chamber;   pouring the molten first alloy charge from the first melt box into the initial casting mold;   moving the initial casting mold out of the melt chamber and removing the initial casting mold from the furnace system;   loading the subsequent casting mold into the loading chamber of the furnace system;   moving the subsequent casting mold to the casting position within the melt chamber;   pouring the molten second alloy charge from the second melt box into the subsequent casting mold; and   moving the subsequent casting mold out of the melt chamber and removing the subsequent casting mold from the furnace system.   
     
     
         12 . The method according to  claim 11 , further comprising:
 reducing the pressure in the melt chamber; and   reducing the pressure in the loading chamber.   
     
     
         13 . The method according to  claim 12 , further comprising:
 reducing the pressure in the melt chamber to about 5 mTorr; and   reducing the pressure in the loading chamber to about 100 mTorr.   
     
     
         14 . The method according to  claim 11 , wherein the initial casting mold and the subsequent casting mold are each pre-heated to a temperature of about 800° C. to about 1,000° C. 
     
     
         15 . The method according to  claim 11 , wherein the melt chamber is raised to a temperature of about 1,300° C. to melt either or both of the first and second alloy charges within the first melt box and the second melt box. 
     
     
         16 . The method according to  claim 11 , wherein a casting mold removed from the furnace system is allowed to cool such that a casting in the casting mold has an equiaxed structure. 
     
     
         17 . The method according to  claim 11 , further comprising reloading an alloy charge into either or both of the first melt box and the second melt box after either the initial casting mold or the subsequent casting mold is moved out of the melt chamber. 
     
     
         18 . The method according to  claim 11 , further comprising:
 loading a third alloy charge into a third melt box within the melt chamber of the furnace system;   melting the third alloy charge with the first and second alloy charges to be molten;   pre-heating a third casting mold;   following removal of the subsequent casting mold, loading the third casting mold into the loading chamber of the furnace system;   moving the third casting mold to a casting position within the melt chamber;   pouring the molten third alloy charge from the third melt box into the third casting mold;   moving the third casting mold out of the melt chamber and removing the third casting mold from the furnace system.   
     
     
         19 . The method according to  claim 18 , further comprising:
 loading a fourth alloy charge into a fourth melt box within the melt chamber of the furnace system;   melting the fourth alloy charge with the first and second alloy charges to be molten;   pre-heating a fourth casting mold;   following removal of the third casting mold, loading the fourth casting mold into the loading chamber of the furnace system;   moving the fourth casting mold to a casting position within the melt chamber;   pouring the molten third alloy charge from the fourth melt box into the fourth casting mold;   moving the fourth casting mold out of the melt chamber and removing the fourth casting mold from the furnace system.