Method to produce composite material with a hard inner layer with deep draw capability

Abstract

A method for producing a composite metallic material having a soft outer layer of a first metal or metal alloy and a hard inner layer of a second metal or metal alloy includes first selecting the soft layer and the hard layer according to the desired properties of the combined layers. The soft layer is then bonded with the hard layer. Finally, the bonded layers are annealed at a temperature within the range of 700-1200 degrees Fahrenheit to secure the bond and enhance formability.

What is claimed is: 
     
         1 . A method for producing a composite metallic material having a soft outer layer and a hard inner layer comprising the steps of:
 a. identifying the soft layer and the hard layer according to the desired properties of the combined layers;   b. bonding the soft layer with the hard layer; and   c. annealing the bonded layers at a temperature within the range of 700-1200 degrees Fahrenheit to secure the bond and enhance formability.   
     
     
         2 . The method as described in  claim 1  wherein step a) further comprises selecting the soft outer layer from a group consisting of copper or aluminum. 
     
     
         3 . The method as described in  claim 1  wherein step a) further comprises the step of selecting the soft outer layer having a Rockwell hardness on the B scale of less than HRB 50. 
     
     
         4 . The method as described in  claim 1  wherein step a) further comprises the step of selecting the hard outer layer having a Rockwell hardness on the B scale of greater than HRB 50. 
     
     
         5 . The method as described in  claim 1  wherein step a) further comprises selecting the hard outer layer from a group consisting of steel, stainless steel, or titanium. 
     
     
         6 . The method as described in  claim 1  wherein step b) includes cold-roll bonding the soft layer with the hard layer. 
     
     
         7 . The method as described in  claim 1  wherein the annealing performed in step c) is in a continuous process and in a controlled atmosphere. 
     
     
         8 . The method as described in  claim 7  wherein the annealing is performed a controlled atmosphere selected from the group consisting of hydrogen, nitrogen, or a mixture of hydrogen and nitrogen. 
     
     
         9 . A method for producing a composite metallic material having a soft outer layer and a hard inner layer comprising the steps of:
 a. identifying the soft layer and the hard layer according to the desired properties of the combined layers;   b. feeding the soft layer and the hard layer into a bonding mill to bond the soft layer with the hard layer; and   c. annealing the bonded layers at a temperature of greater than 700 degrees Fahrenheit and less than 1200 degrees Fahrenheit to secure the bond and enhance formability.   
     
     
         10 . The method as described in  claim 9  wherein step a) further comprises selecting the soft outer layer from a group consisting of copper or aluminum. 
     
     
         11 . The method as described in  claim 9  wherein step a) further comprises the step of selecting the soft outer layer having a Rockwell hardness on the B scale of less than HRB 50. 
     
     
         12 . The method as described in  claim 1  wherein step a) further comprises the step of selecting the hard outer layer having a Rockwell hardness on the B scale of greater than HRB 50. 
     
     
         13 . The method as described in  claim 12  wherein step a) further comprises selecting the hard outer layer from a group consisting of steel, stainless steel, or titanium. 
     
     
         14 . The method as described in  claim 9  wherein step b) includes cold-roll bonding the soft layer with the hard layer. 
     
     
         15 . The method as described in  claim 9  wherein the annealing performed in step c) is in a continuous process and in a controlled atmosphere. 
     
     
         16 . The method as described in  claim 15  wherein the annealing is performed a controlled atmosphere selected from the group consisting of hydrogen, nitrogen, or a mixture of hydrogen and nitrogen.