Composite metal article and method of making

Abstract

A composite metal article from two dissimilar metals is prepared. A metal base is comprised of a first metal and having first and second opposing surfaces and a least one longitudinally-positioned depression in each of the first and second opposing surfaces for receiving a wire. An elongated metal element comprised of a second metal is introduced into each of the at least one first and second depressions of the metal base to form a composite assembly, and the composite assembly is heated under pressure to urge the adjacent surfaces of the second metal elements and the depressions together to form a bonded article.

1 . A method of making a composite article, comprising:
 (a) providing a metal base comprised of a first metal and having first and second opposing surfaces, said base having at least one longitudinal depression in at least one of said first and second opposing surfaces;   (b) introducing a wire comprised of a second metal into said at least one depression of the metal base to form a composite assembly, said second metal comprising a cutting tool grade steel and being harder than the first metal;   (c) heating the composite assembly under pressure to urge the adjacent surfaces of the wire and the at least one depression together to form a bonded article and to reduce the thickness of the metal base at least at the wire/base interface; and   (d) constraining a lateral spread of the composite assembly during at least a portion of the step of heating under pressure under conditions to maintain a lateral bonding pressure on the composite assembly.   
   
   
       2 . The method of  claim 1 , wherein the step of heating the composite assembly under pressure in step (c) comprises reducing the thickness of the metal base to the extent that a transverse cross-section of at least a portion of the bonded article includes substantially no first metal. 
   
   
       3 . The method of  claim 1 , wherein the step of heating the composite assembly under pressure in step (c) comprises reducing the thickness of the metal base to 1 to 70% of a transverse cross-section of the article at the metal base's thinnest point. 
   
   
       4 . The method of  claim 1 , wherein a pair of metal bases is provided, each metal base having at least one longitudinal depression, and the wire is introduced into the longitudinal depression of each metal base. 
   
   
       5 . The method of  claim 1 , wherein the constraining step (d) is carried out using a mated pair of male/female rolls. 
   
   
       6 . The method of  claim 1 , wherein the step of providing a metal base having at least one longitudinal depression in step (a) comprises providing the at least one depression in the form selected from the group consisting of v-groove, square groove, rounded groove, and rectangular groove. 
   
   
       7 . The method of  claim 1 , wherein the step of providing a metal base having at least one longitudinal depression in step (a) comprises providing at least one depression located in the center of the first opposing surface of the metal base. 
   
   
       8 . The method of  claim 1 , wherein the step of providing a metal base having at least one longitudinal depression in step (a) comprises providing at least one depression offset from the center of the first opposing surface of the metal base. 
   
   
       9 . The method of  claim 1 , wherein the step of providing a metal base comprises providing the first metal selected from the group consisting of hot or cold rolled metal or metal alloys that are spring-like. 
   
   
       10 . The method of  claim 1 , wherein the second metal is selected from the group consisting of high speed steels. 
   
   
       11 . The method of  claim 1 , comprising forming a metallurgical bond between the first and second metals. 
   
   
       12 . The method of  claim 1 , wherein the constraining step (d) is carried out using a turks head. 
   
   
       13 . The method of  claim 12 , wherein side rolls of the turks head are forward offset at a distance from a set of bonding rolls at an entrance side of said bonding rolls, so that the side rolls of the turks head apply an opposing force to the composite assembly to constrain lateral spread of the composite assembly. 
   
   
       14 . The method of  claim 1 , wherein the step of providing a metal base in step (a) comprises providing a sheet or strip. 
   
   
       15 . The method of  claim 14 , wherein the step of providing a sheet or strip comprises providing a sheet having an aspect ratio of greater than 5:1. 
   
   
       16 . The method of  claim 1 , wherein the metal base includes depressions in the first and second surfaces, said metal base having a cross-section with an appearance of a barbell. 
   
   
       17 . The method of  claim 16 , wherein the metal base has an aspect ratio of about 1:1 to about 1:10. 
   
   
       18 . The method of  claim 1 , further comprising rolling the composite assembly to form a rectangular bar. 
   
   
       19 . The method of  claim 18 , further comprising trimming an edge of the bar to expose an interior surface comprising the second metal. 
   
   
       20 . The method of  claim 1 , wherein the wire has a cross-sectional shape selected from the group consisting of round, square, oval, polygonal, rectangular, and rhomboid. 
   
   
       21 . The method of  claim 20 , comprising providing the at least one longitudinal depression of the metal base of step (a) in a shape that is complementary to the shape of the wire of step (b). 
   
   
       22 . The method of  claim 1 , wherein the wire is a composite metal wire. 
   
   
       23 . The method of  claim 22 , wherein the composite metal wire comprises upper and lower regions comprised of the second metal and at least one inner region disposed between the upper and lower regions comprised of a third metal. 
   
   
       24 . The method of  claim 23 , wherein the third metal is different than the first metal. 
   
   
       25 . The method of  claim 23 , wherein the third metal is the same as the first metal. 
   
   
       26 . The method of  claim 22 , wherein the composite wire is made by:
 contacting a first metal member and a second metal member under heat and pressure to urge the adjacent surfaces of the first and second metal members together to form a bonded wire.   
   
   
       27 . The method of  claim 1 , wherein the step of providing a metal base in step (a) comprises providing a metal base having at least one depression on each of said first and second surfaces. 
   
   
       28 . The method of  claim 27 , wherein the step of providing a metal base in step (a) comprises providing the depression of the first opposing surface and the depression of the second opposing surface opposite one another. 
   
   
       29 . The method of  claim 27 , wherein the constraining step (d) is carried out using a mated pair of male/female rolls. 
   
   
       30 . The method of  claim 27 , wherein the step of providing a metal base in step (a) comprises providing the at least one depression in the form selected from the group consisting of v-groove, square groove, rounded groove, and rectangular groove. 
   
   
       31 . The method of  claim 27 , wherein the constraining step (d) is carried out using a turks head. 
   
   
       32 . The method of  claim 31 , wherein side rolls of the turks head are forward offset at a distance from a set of bonding rolls at an entrance side of said bonding rolls, so that the side rolls of the turks head apply an opposing force to the composite assembly to constrain lateral spread of the composite assembly. 
   
   
       33 . The method of  claim 27 , wherein the wire has a cross-sectional shape selected from the group consisting of round, square, oval, polygonal, rectangular, and rhomboid. 
   
   
       34 . The method of  claim 33 , comprising providing the at least one longitudinal depression of the metal base of step (a) in a shape that is complementary to the shape of the wire of step (b). 
   
   
       35 . The method of  claim 27 , wherein the wire is a composite metal wire. 
   
   
       36 . The method of  claim 35 , wherein the composite metal wire comprises upper and lower regions comprised of the second metal and at least one inner region disposed between the upper and lower regions comprised of a third metal. 
   
   
       37 . The method of  claim 36 , wherein the third metal is different than the first metal. 
   
   
       38 . The method of  claim 36 , wherein the third metal is the same as the first metal. 
   
   
       39 . The method of  claim 35 , wherein the composite wire is made by:
 contacting a first metal member and a second metal member under heat and pressure to urge the adjacent surfaces of the first and second metal members together to form a bonded wire.   
   
   
       40 . The method of  claim 27 , wherein the step of providing a metal base in step (a) comprises providing at least one depression offset from the center of the first opposing surface of the metal base. 
   
   
       41 . The method of  claim 27 , wherein applying pressure in step (c) is accomplished by rolling or swaging. 
   
   
       42 . The method of  claim 41 , wherein applying pressure is accomplished by rolling. 
   
   
       43 . The method of  claim 42 , wherein said rolling comprises a plurality of rolling steps. 
   
   
       44 . The method of  claim 43 , wherein the bond strength between the wire and the metal base increases during the plurality of rolling steps. 
   
   
       45 . The method of  claim 43 , wherein said rolling comprises 2-10 rolling steps. 
   
   
       46 . The method of  claim 43 , wherein said rolling comprises 3-6 rolling steps. 
   
   
       47 . The method of  claim 43 , wherein at least a first rolling step consolidates the composite assembly and constrains lateral spread. 
   
   
       48 . The method of  claim 47 , wherein at least one subsequent rolling step reduces the thickness of the composite assembly. 
   
   
       49 . The method of  claim 1 , wherein applying pressure in step (c) is accomplished by rolling or swaging. 
   
   
       50 . The method of  claim 49 , wherein applying pressure is accomplished by rolling. 
   
   
       51 . The method of  claim 50 , wherein said rolling comprises a plurality of rolling steps. 
   
   
       52 . The method of  claim 51 , wherein the bond strength between the wire and the metal base increases during the plurality of rolling steps. 
   
   
       53 . The method of  claim 51 , wherein said rolling comprises 2-10 rolling steps. 
   
   
       54 . The method of  claim 51 , wherein said rolling comprises 3-6 rolling steps. 
   
   
       55 . The method of  claim 51 , wherein at least a first rolling step consolidates the composite assembly and constrains lateral spread. 
   
   
       56 . The method of  claim 55 , wherein at least one subsequent rolling step reduces the thickness of the composite assembly. 
   
   
       57 . The method of  claim 1 , wherein the step of providing a metal base in step (a) comprises providing a metal base having two or more depressions on at least one of said first and second opposing surfaces. 
   
   
       58 . The method of  claim 57 , wherein the step of providing a metal base in step (a) comprises providing at least one depression located in the center of the first opposing surface of the metal base. 
   
   
       59 . The method of  claim 57 , wherein the step of providing a metal base in step (a) comprises providing at least one depression offset from the center of the first opposing surface of the metal base. 
   
   
       60 . The method of  claim 57 , wherein applying pressure in step (c) is accomplished by rolling or swaging. 
   
   
       61 . The method of  claim 60 , wherein applying pressure is accomplished by rolling. 
   
   
       62 . The method of  claim 61 , wherein said rolling comprises a plurality of rolling steps. 
   
   
       63 . The method of  claim 62 , wherein the bond strength between the wire and the metal base increases during the plurality of rolling steps. 
   
   
       64 . The method of  claim 62 , wherein said rolling comprises 2-10 rolling steps. 
   
   
       65 . The method of  claim 62 , wherein said rolling comprises 3-6 rolling steps. 
   
   
       66 . The method of  claim 62 , wherein at least a first rolling step consolidates the composite assembly and constrains lateral spread. 
   
   
       67 . The method of  claim 66 , wherein at least one subsequent rolling step reduces the thickness of the composite assembly. 
   
   
       68 . A method of making a composite article having two dissimilar metals, comprising:
 (a) providing a metal base comprised of a first metal and having first and second opposing surfaces;   (b) positioning at least one wire comprised of a second metal at a location on at least one of said first and second surfaces, wherein the second metal comprises a cutting tool grade steel and is harder than the first metal;   (c) restricting the lateral movement of the wire relative to its location on said surface to form a composite assembly; and   (d) heating the composite assembly under pressure to urge the adjacent surfaces of the at least one wire and the metal base together to form a bonded article and to reduce the thickness of the metal base at the base/wire interface, wherein at least a first rolling step consolidates the composite assembly and maintains a lateral bonding pressure on the composite assembly.   
   
   
       69 . The method of  claim 68 , wherein the step (c) of restricting the lateral movement of the wire relative to its position on the metal base comprises providing at least one longitudinally-positioned depression in at least one of said first and second surfaces for receiving said wire. 
   
   
       70 . The method of  claim 68 , wherein the composite assembly is pressed by rolling the composite assembly through a roll having a groove in the roll surface in the direction of rolling, wherein the wire is engaged in the groove and the pressure of the roll on the wire and the metal base restricts lateral movement. 
   
   
       71 . The method of  claim 68 , wherein at least one subsequent rolling step reduces the thickness of the composite assembly. 
   
   
       72 . The method of  claim 68 , wherein the step of heating the composite assembly under pressure in step (d) comprises thinning the metal base to the extent that a transverse cross-section of at least a portion of the bonded article includes substantially no first metal. 
   
   
       73 . The method of  claim 68 , wherein the step of providing a metal base comprises providing the first metal selected from the group consisting of hot or cold rolled metal or metal alloys that are spring-like. 
   
   
       74 . The method of  claim 68 , wherein the second metal is selected from the group consisting of high speed steels. 
   
   
       75 . The method of  claim 68  comprising forming a metallurgical bond between the first and second metals.