System and Method for Integrally Casting Multilayer Metallic Structures

Abstract

A process of making a multilayer metallic casting includes steps of simultaneously forming a first layer of a first metallic material and a second layer of a second metallic material using a high speed continuous casting process, and continuously bonding the first and second layers to form a integrally cast multilayer metallic casting. The process may be performed using a twin-roll type continuous casting system having a continuous casting mold that includes a first mold compartment for receiving a molten first metallic material and a second mold compartment for receiving a molten second metallic. The molten first and second types of metallic material are quickly solidified into semi-solid shells and are pressed together by opposed casting rolls, creating a metallurgical bond between the first and second types of metallic material in order to form an integrally cast multilayer metallic casting. The process permits the high speed efficient manufacturing of near net shape multilayer metallic castings.

1 . A method of making a multilayer metallic casting, comprising:
 simultaneously forming a first layer of a first metallic material and a second layer of a second metallic material using a high speed continuous casting process; and   continuously bonding said first and second layers to form a integrally cast multilayer metallic casting.   
     
     
         2 . A method of making a multilayer metallic casting according to  claim 1 , wherein said step of continuously bonding said first and second layers is performed while said first and second layers are still at elevated temperatures. 
     
     
         3 . A method of making a multilayer metallic casting according to  claim 2 , wherein said step of continuously bonding said first and second layers is performed while at least a portion of one of said first and second layers is in at least a semi-molten state. 
     
     
         4 . A method of making a multilayer metallic casting according to  claim 3 , further comprising a step of providing additional heating to at least one surface of at least one of said first and second layers that is to be bonded to a surface of the other of said first and second layers in order to form the integrally cast multilayer metallic casting. 
     
     
         5 . A method of making a multilayer metallic casting according to  claim 1 , wherein said step of simultaneously forming a first layer of first layer of metallic material and a second layer of a second type of metallic material using a continuous casting process is performed using a continuous casting mold having a first mold compartment holding molten metallic material of the first type; a second mold compartment holding molten metallic material of the second type; and a separating dam defining a divider between said first and second mold compartments. 
     
     
         6 . A method of making a multilayer metallic casting according to  claim 1 , wherein said step of simultaneously forming a first layer of the first type of metallic material and a second layer of the second type of metallic material is performed using a continuous casting machine having a first casting roll for forming and cooling one of said first and second layers. 
     
     
         7 . A method of making a multilayer metallic casting according to  claim 6 , wherein said step of simultaneously forming a first layer of the first type of metallic material and a second layer of the second type of metallic material is further performed using a second casting roll for forming and cooling the other of said first and second layers. 
     
     
         8 . A method of making a multilayer metallic casting according to  claim 1 , said first type of metallic material and said second type of metallic material are not the same material. 
     
     
         9 . A method of making a multilayer metallic casting according to  claim 1 , wherein said high speed continuous casting process operates at a casting speed that is substantially within a range of about 40 to about 160 meters per minute. 
     
     
         10 . A method of making a multilayer metallic casting according to  claim 9 , wherein said high speed continuous casting process operates at a casting speed that is substantially within a range of about 60 to about 120 meters per minute. 
     
     
         11 . A method of making a multilayer metallic casting according to  claim 10 , wherein said high speed continuous casting process operates at a casting speed that is substantially within a range of about 80 to about 100 meters per minute. 
     
     
         12 . A method of making a multilayer metallic casting according to  claim 1 , wherein said continuous casting process is performed to produce a casting that is in near net shape form. 
     
     
         13 . A method of making a multilayer metallic casting, comprising:
 simultaneously forming a first layer of a first metallic material and a second layer of a second metallic material; and   continuously bonding said first and second layers to form a final integral multilayer metallic casting that is in near net shape form.   
     
     
         14 . A method of making a multilayer metallic casting according to  claim 13 , wherein said step of continuously bonding said first and second layers is performed while said first and second layers are still at elevated temperatures. 
     
     
         15 . A method of making a multilayer metallic casting according to  claim 14 , wherein said step of continuously bonding said first and second layers is performed while at least a portion of one of said first and second layers is in at least a semi-molten state. 
     
     
         16 . A method of making a multilayer metallic casting according to  claim 15 , further comprising a step of providing additional heating to at least one surface of at least one of said first and second layers that is to be bonded to a surface of the other of said first and second layers in order to form the integrally cast multilayer metallic casting. 
     
     
         17 . A method of making a multilayer metallic casting according to  claim 13 , wherein said step of simultaneously forming a first layer of first layer of metallic material and a second layer of a second type of metallic material using a continuous casting process is performed using a continuous casting mold having a first mold compartment holding molten metallic material of the first type; a second mold compartment holding molten metallic material of the second type; and a separating dam defining a divider between said first and second mold compartments. 
     
     
         18 . A method of making a multilayer metallic casting according to  claim 13 , wherein said step of simultaneously forming a first layer of the first type of metallic material and a second layer of the second type of metallic material is performed using a continuous casting machine having a first casting roll for forming and cooling one of said first and second layers. 
     
     
         19 . A method of making a multilayer metallic casting according to  claim 18 , wherein said step of simultaneously forming a first layer of the first type of metallic material and a second layer of the second type of metallic material is further performed using a second casting roll for forming and cooling the other of said first and second layers. 
     
     
         20 . A method of making a multilayer metallic casting according to  claim 13 , said first type of metallic material and said second type of metallic material are not the same material.