Method for bonding a tantalum structure to a cobalt-alloy substrate

Abstract

A method for bonding a porous tantalum structure to a substrate is provided. The method comprises providing a substrate comprising cobalt or a cobalt-chromium alloy; an interlayer consisting essentially of at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof; and a porous tantalum structure. Heat and pressure are applied to the substrate, the interlayer, and the porous tantalum structure to achieve solid-state diffusion between the substrate and the interlayer and between the interlayer and the porous tantalum structure.

1 - 14 . (canceled) 
     
     
         15 . A method for bonding a porous tantalum structure to a substrate, comprising:
 providing a substrate comprising cobalt or a cobalt-chromium alloy;   providing a porous tantalum structure;   applying an interlayer consisting essentially of at least one of hathium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the substrate, wherein the interlayer is applied to the surface by at least one of thermal spraying, plasma spraying, electron beam deposition, laser deposition, chemical vapor deposition, or electrodeposition, and wherein the interlayer has a porosity of between about 20% and about 40%;   positioning the porous tantalum structure in contact with the interlayer thereby forming an assembly, wherein the interlayer is between the porous tantalum structure and the substrate; and   applying heat and pressure to the assembly for a time sufficient to concurrently achieve solid-state diffusion between the substrate and the interlayer and solid-state diffusion between the interlayer and the porous tantalum structure.   
     
     
         16 . The method of  claim 15 , wherein the interlayer is at least about 0.020 inches thick. 
     
     
         17 . The method of  claim 15 , wherein the interlayer is at least about 0.010 inches thick. 
     
     
         18 . The method of  claim 15 , wherein applying the interlayer includes plasma spraying the interlayer onto the surface in at least a partial vacuum. 
     
     
         19 . The method of  claim 15 , wherein applying pressure includes applying at least approximately 200 psi to the assembly. 
     
     
         20 . The method of  claim 15 , wherein said interlayer has a top surface and a bottom surface, and wherein said applying heat and pressure to the assembly achieves solid-state diffusion between the substrate and the bottom surface of the interlayer and solid-state diffusion between the top surface of the interlayer and the porous tantalum structure. 
     
     
         21 . The method of  claim 15 , wherein applying heat includes heating the assembly to less than about 1000° C. in a vacuum environment. 
     
     
         22 . The method of  claim 15 , wherein the interlayer has a thickness of at least about 0.010 inches and applying heat and pressure includes applying a pressure of at least about 200 psi and heating the assembly to at least about 540° C. for at least one hour to achieve solid-state diffusion between the substrate and the interlayer and between the interlayer and the porous tantalum structure. 
     
     
         23 . A method for bonding a porous tantalum structure to a substrate, comprising:
 providing a substrate comprising cobalt or a cobalt-chromium alloy;   applying an interlayer consisting essentially of at least one of hathium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the substrate, wherein the interlayer is applied to the surface by at least one of thermal spraying, plasma spraying, electron beam deposition, laser deposition, chemical vapor deposition, electrodeposition, or cold spray coating, and wherein the interlayer has a porosity of between about 20% and about 40%;   applying heat and pressure to the interlayer and the substrate for a time sufficient to achieve solid-state diffusion between the substrate and the interlayer thereby forming a subassembly;   positioning a porous tantalum structure in contact with the interlayer portion of the subassembly, thereby forming an assembly; and   applying heat and pressure to the assembly for a time sufficient to achieve solid-state diffusion between the interlayer and the porous tantalum structure.   
     
     
         24 . The method of  claim 23 , wherein the interlayer is at least about 0.010 inches thick. 
     
     
         25 . The method of  claim 23 , wherein applying the interlayer includes plasma spraying the interlayer onto the surface of the substrate in at least a partial vacuum. 
     
     
         26 . The method of  claim 23 , wherein applying heat to the assembly includes heating the assembly to less than about 1000° C. in a vacuum environment. 
     
     
         27 . The method of  claim 23 , wherein a diffusion bond depth between the interlayer and the substrate is substantially the same as a diffusion bond depth between the interlayer and the porous tantalum structure. 
     
     
         28 . A method for bonding a porous tantalum structure to a substrate, comprising:
 providing a porous tantalum structure;   applying an interlayer consisting essentially of at least one of hathium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the porous tantalum structure, wherein the interlayer is applied to the surface by at least one of thermal spraying, plasma spraying, electron beam deposition, laser deposition, chemical vapor deposition, or electrodeposition;   applying heat and pressure to the interlayer and the porous tantalum structure for a time sufficient to achieve solid-state diffusion between the porous tantalum structure and the interlayer thereby forming a subassembly;   positioning a substrate comprising cobalt or a cobalt-chromium alloy in contact with the interlayer portion of the subassembly, thereby forming an assembly; and   applying heat and pressure to the assembly for a time sufficient to achieve solid-state diffusion between the interlayer and the substrate.   
     
     
         29 . The method of  claim 28 , wherein the interlayer is at least about 0.010 inches thick. 
     
     
         30 . The method of  claim 28 , wherein applying the interlayer includes plasma spraying the interlayer onto the surface of the substrate in at least a partial vacuum. 
     
     
         31 . The method of  claim 28 , wherein the interlayer has a porosity of between about 20% and about 40%. 
     
     
         32 . The method of  claim 28 , wherein applying pressure to the assembly includes applying at least approximately 200 psi to the assembly. 
     
     
         33 . The method of  claim 28 , wherein a diffusion bond depth between the interlayer and the substrate is substantially the same as a diffusion bond depth between the interlayer and the porous tantalum structure. 
     
     
         34 . The method of  claim 28 , wherein applying heat to the assembly includes heating the assembly to less than about 1000° C. in a vacuum environment.