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 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 gradually 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 large scale efficient manufacturing of near net shape multilayer metallic castings.

1 - 20 . (canceled) 
     
     
         21 . 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 continuous casting process, 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; and   continuously bonding said first and second layers to form a integrally cast multilayer metallic casting.   
     
     
         22 . A method of making a multilayer metallic casting according to  claim 21 , wherein said step of continuously bonding said first and second layers is performed while said first and second layers are still at elevated temperatures. 
     
     
         23 . A method of making a multilayer metallic casting according to  claim 22 , 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. 
     
     
         24 . A method of making a multilayer metallic casting according to  claim 23 , 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. 
     
     
         25 . A method of making a multilayer metallic casting according to  claim 21 , 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. 
     
     
         26 . A method of making a multilayer metallic casting according to  claim 21 , 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. 
     
     
         27 . A method of making a multilayer metallic casting according to  claim 21 , said first type of metallic material and said second type of metallic material are not the same material. 
     
     
         28 . A method of making a multilayer metallic casting, comprising:
 supplying a molten first type of metal material to a continuous casting mold;   supplying a molten second type of metallic material to the continuous casting mold; and   continuously casting a multilayer metallic casting using a roll casting machine from said first and second types of metallic material using said continuous casting mold.   
     
     
         29 . A method of making a multilayer metallic casting according to  claim 28 , wherein said step of supplying a molten first type of metallic material is performed using a first tundish, and said step of supplying a second type of metallic material to the continuous casting mold is performed using a second tundish. 
     
     
         30 . A method of making a multilayer metallic casting according to  claim 28 , wherein said step of supplying a molten first type of metallic material is performed by supplying the first type of molten metallic material to a first mold compartment of the continuous casting mold, and wherein said step of supplying a molten second type of metallic material is performed by supplying the molten second type of metallic material to a second mold compartment of the continuous casting mold. 
     
     
         31 . A method of making a multilayer metallic casting according to  claim 30 , wherein said step of continuously casting a multilayer metallic casting unit is performed by using a first casting roll that is integral with said continuous casting mold to form and cool one of the molten first and second types of metallic material into a first semi-solid shell and by using a second casting roll to form and cool the other of the molten first and second types of metallic material into a second semi-solid shell. 
     
     
         32 . A method of making a multilayer metallic casting according to  claim 31 , wherein said step of continuously casting a multilayer metallic casting is further performed by pressing said first and second semi-solid shells together to form a bonded integrally cast multilayer metallic casting. 
     
     
         33 . A method of making a multilayer metallic casting according to  claim 32 , wherein said step of pressing said first and second semi-solid shells together to form a bonded integrally cast multilayer metallic casting is performed by the first and second casting rolls. 
     
     
         34 . A method of making a multilayer metallic casting according to  claim 31 , wherein said step of continuously casting a multilayer metallic casting having a integrally cast multilayer metallic casting is further performed by applying additional heating to a surface of at least one of said first and second semi-solid shells that is opposite from the respective casting roll. 
     
     
         35 . 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 continuous casting process, 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; and   continuously bonding said first and second layers by pressing said first and second layers together to form a bonded integrally cast multilayer metallic casting.   
     
     
         36 . A method of making a multilayer metallic casting according to  claim 35 , wherein said step of pressing said first and second layers together to form a bonded integrally cast multilayer metallic casting is performed using at least one casting roll. 
     
     
         37 . A method of making a multilayer metallic casting according to  claim 35 , wherein said step of simultaneously forming a first layer of a first metallic material and a second layer of a second metallic material using a continuous casting process is performed by using a first casting roll to form and cool one of the molten first and second types of metallic material into a first semi-solid shell and by using a second casting roll to form and cool the other of the molten first and second types of metallic material into a second semi-solid shell. 
     
     
         38 . A method of making a multilayer metallic casting according to  claim 37 , wherein said step of pressing said first and second semi-solid shells together to form a bonded integrally cast multilayer metallic casting is performed by the first and second casting rolls. 
     
     
         39 . A method of making a multilayer metallic casting according to  claim 35 , wherein said step simultaneously forming a first layer of a first metallic material and a second layer of a second metallic material using a continuous casting process is further performed by applying additional heating to a surface of at least one of said first and second layers.