METHOD FOR BONDING A TANTALUM STRUCTURE TO A COBALT-ALLOY SUBSTRATE

• US 20090098310A1
• Filed: 10/10/2007
• Published: 04/16/2009
• Est. Priority Date: 10/10/2007
• Status: Active Grant

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Peek, Lawrence F., Allen, Steve M., Anderson, Jeffrey P., Gorhe, Devendra, Hippensteel, Gregory M.
• Granted Patent: US 8,608,049 B2
• Time in Patent Office: Days
• US Class Current: 427/576
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2002/3092 having an open-celled or open-pored structure
• CPC Class Codes: A61F 2002/30929 having at least two superposed coatings
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00544 Coating made of tantalum or Ta-based alloys
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B23K 20/16 with interposition of special material to facilitate connection of the parts, e.g. material for absorbing or producing gas
• CPC Class Codes: B23K 20/233 without ferrous layer
• CPC Class Codes: B23K 2103/08 Non-ferrous metals or alloys
• CPC Class Codes: B23K 2103/18 Dissimilar materials
• CPC Class Codes: B23K 2103/26 Alloys of Nickel and Cobalt and Chromium
• CPC Class Codes: Y10T 428/12479 Porous [e.g., foamed, spongy, cracked, etc.]
• CPC Class Codes: Y10T 428/12806 Refractory [Group IVB, VB, or VIB] metal-base component

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.

Claims

1. A method for bonding a porous tantalum structure to a substrate, comprising:

providing a substrate comprising cobalt or a cobalt-chromium alloy;

providing an interlayer consisting essentially of at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof;

providing a porous tantalum structure;

applying heat and pressure to the substrate and the interlayer for a time sufficient to achieve solid-state diffusion between the substrate and the interlayer; and

applying heat and pressure to the interlayer and the porous tantalum structure for a time sufficient to achieve solid-state diffusion between the interlayer and the porous tantalum structure.

2. The method of claim 1 wherein providing the interlayer includes applying the interlayer to a surface of the substrate;

providing the porous tantalum structure includes positioning the porous tantalum structure in contact with the interlayer, thereby forming an assembly; and

the steps of applying heat and pressure to the substrate and the interlayer and applying heat and pressure to the interlayer and the porous tantalum structure occur concurrently by applying heat and pressure to the assembly.

3. The method of claim 1 wherein providing the interlayer includes applying the interlayer to a surface of the substrate;

applying heat and pressure to the substrate and the interlayer includes applying heat and pressure to the substrate and the interlayer for a time sufficient to achieve solid-state diffusion between the substrate and the interlayer, thereby forming a subassembly;

providing the porous tantalum structure occurs subsequent to the step of applying heat and pressure to the substrate and the interlayer and includes positioning the porous tantalum structure in contact with the interlayer portion of the subassembly, thereby forming an assembly; and

applying heat and pressure to the interlayer and the porous tantalum structure includes applying heat and pressure to the assembly.

4. The method of claim 1 wherein providing the interlayer includes applying the interlayer to a surface of the porous tantalum structure;

applying heat and pressure to the interlayer and the porous tantalum structure includes 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;

providing the substrate occurs subsequent to the step of applying heat and pressure to the interlayer and the porous tantalum structure and includes positioning the substrate in contact with the interlayer portion of the subassembly, thereby forming an assembly; and

applying heat and pressure to the substrate and the interlayer includes applying heat and pressure to the assembly.

5. 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 hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the substrate;

positioning a porous tantalum structure in contact with the interlayer, thereby forming an assembly; and

applying heat and pressure to the assembly for a time sufficient to achieve solid-state diffusion between the substrate and the interlayer and solid-state diffusion between the interlayer and the porous tantalum structure.

6. The method of claim 5 wherein the interlayer is a pre-formed sheet that conforms to the surface of the substrate such that the assembly comprises the substrate, the pre-formed sheet, and the porous tantalum structure.

7. The method of claim 6 wherein the pre-formed sheet is at least about 0.016 inches thick.

8. The method of claim 5 wherein applying the interlayer includes depositing the interlayer as a coating onto the surface of the substrate by at least one of thermal spraying, electron beam deposition, laser deposition, chemical vapor deposition, electrodeposition, or cold spray coating the interlayer onto the surface of the substrate.

9. The method of claim 8 wherein the coating is at least about 0.010 inches thick.

10. The method of claim 5 wherein applying the interlayer includes plasma spraying the interlayer onto the surface of the substrate in at least a partial vacuum.

11. The method of claim 5 wherein applying pressure includes applying at least approximately 200 psi to the assembly.

12. The method of claim 5 wherein applying pressure includes applying a pressure that is less than a compressive yield strength of the porous tantalum structure.

13. The method of claim 5 wherein heating includes heating to less than about 1000°

C. in a vacuum environment.

14. The method of claim 5 wherein the interlayer is a pre-formed sheet having a thickness of at least about 0.016 inches and applying heat and pressure includes applying a pressure of 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 pre-formed sheet and between the pre-formed sheet and the porous tantalum structure.

15. A method for bonding a porous tantalum structure to a substrate, comprising:

providing a substrate comprising cobalt or a cobalt-chromium alloy;

positioning an interlayer sheet having a thickness of at least about 0.016 inches, the interlayer sheet comprising at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof in contact with the substrate;

positioning a porous tantalum structure in contact with the interlayer sheet, thereby forming an assembly;

applying a pressure of at least about 200 psi to the assembly; 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 sheet and between the interlayer sheet and the porous tantalum structure.

16. 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 hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the substrate;

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.

17. The method of claim 16 wherein the interlayer is a pre-formed sheet that conforms to the surface of the substrate.

18. The method of claim 17 wherein the pre-formed sheet is at least about 0.016 inches thick.

19. The method of claim 16 wherein applying the interlayer includes depositing the interlayer as a coating onto the surface of the substrate by at least one of thermal spraying, electron beam deposition, laser deposition, chemical vapor deposition, electrodeposition, or cold spray coating the interlayer onto the surface of the substrate.

20. The method of claim 19 wherein the coating is at least about 0.010 inches thick.

21. 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 hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof to a surface of the porous tantalum structure;

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.

22. The method of claim 21 wherein the interlayer is a pre-formed sheet that conforms to the surface of the substrate.

23. The method of claim 22 wherein the pre-formed sheet is at least about 0.016 inches thick.

24. The method of claim 21 wherein applying the interlayer includes depositing the interlayer as a coating onto the surface of the porous tantalum structure by at least one of thermal spraying, electron beam deposition, laser deposition, chemical vapor deposition, electrodeposition, or cold spray coating the interlayer onto the surface of the porous tantalum structure.

25. The method of claim 24 wherein the coating is at least about 0.010 inches thick.