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

• US 20110230973A1
• Filed: 04/22/2011
• Published: 09/22/2011
• Est. Priority Date: 10/10/2007
• Status: Abandoned Application

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Miller, David M., Panchison, Clarence M., Scrafton, Joel G., Peek, Lawrence F., Harmon, Casey, Allen, Steve M., Anderson, Jeffrey P., Gorhe, Devendra, Hippensteel, Gregory M.
• Application Number:
  US13/092,169
• Publication Number:
  US 20110230973A1
• Time in Patent Office: Days
• US Class Current: 623/23.6
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/3859 Femoral components
• 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: A61L 27/045 Cobalt or cobalt alloys
• CPC Class Codes: A61L 27/047 Other specific metals or alloys not covered by A61L27/042 - A61L27/045 or A61L27/06
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B23K 20/02 by means of a press ; Diffusion bonding B23K20/001, B23K20/04 take precedence
• CPC Class Codes: B23K 20/023 Thermo-compression bonding
• 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 20/24 Preliminary treatment
• 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: B23K 35/005 at least one of the workpieces being of a refractory metal
• CPC Class Codes: B23K 35/3026 Mn as the principal constituent
• CPC Class Codes: B23K 35/322 : a Pt-group metal as principal constituent
• CPC Class Codes: B23K 35/325 : Ti as the principal constituent

Abstract

Methods for bonding a porous tantalum structure to a substrate are provided. The method includes placing a compressible or porous interlayer between a porous tantalum structure and a cobalt or cobalt-chromium substrate to form an assembly. The interlayer comprising a metal or metal alloy that has solid state solubility with both the substrate and the porous tantalum structure. Heat and pressure are applied to the assembly to achieve solid state diffusion between the substrate and the interlayer and the between the porous tantalum structure and the interlayer.

Claims

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

positioning a compressible interlayer between a porous tantalum structure and a substrate comprising cobalt or cobalt-chromium to form an assembly, wherein the compressible interlayer consists essentially of a metal or alloy that exhibits solid solubility with the porous tantalum structure and the substrate; and

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

2. The method of claim 1 further including compressing at least a portion of the compressible interlayer when the heat and pressure are applied.

3. The method of claim 1 in which positioning a compressible interlayer between the porous tantalum structure and the substrate comprises coating the compressible interlayer on a surface of the porous tantalum structure and placing the interlayer on the surface of the porous tantalum structure in contact with a surface of the substrate.

4. The method of claim 3 wherein the compressible interlayer coated on the porous tantalum structure has a thickness of at least about 0.010 inches prior to the application of heat and pressure.

5. The method of claim 3 in which the compressible interlayer is coated onto the surface of the porous tantalum structure by plasma spraying.

6. The method of claims 1 in which the compressible interlayer has a porosity of at least about 5 percent.

7. The method of claim 1 in which the positioning the compressible interlayer between the porous tantalum structure and the substrate comprises coating the compressible interlayer on a surface of the substrate and placing the interlayer on the surface of the substrate in contact with a surface of the porous tantalum structure.

8. The method of claim 1 in which the interlayer consists essentially of at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof.

9. A method of bonding a porous tantalum structure to a substrate, comprising:

providing a porous tantalum structure in a first configuration;

providing a substrate comprising cobalt or cobalt-chromium;

applying a porous interlayer to a surface of the porous tantalum structure to form a subassembly, said porous interlayer comprising a metal or alloy that is soluble in the solid state with both the porous tantalum structure and the substrate;

bending the subassembly into a second configuration;

contacting a surface of the substrate with the interlayer to create 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.

10. The method of claim 9 further including compressing at least a portion of the porous interlayer when the heat and pressure are applied.

11. The method of claim 9 wherein the porous interlayer has a thickness of at least about 0.010 inches prior to the application of heat and pressure.

12. The method of claim 9 in which the porous interlayer is applied onto the surface of the porous tantalum structure by plasma spraying.

13. The method of claim 9 in which the porous interlayer has a porosity of at least about 5 percent.

14. The method of claim 9 in which the interlayer consists essentially of at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof.

15. The method of claim 9 in which the surface of the substrate comprises a geometrically complex surface.

16. The method of claim 9 in which the porous tantalum structure is substantially flat in the first configuration.

17. An assembly for forming a medical implant, comprising:

a porous tantalum structure;

a substrate comprising cobalt or cobalt-chromium alloy; and

a compressible interlayer between the porous tantalum structure and the substrate, wherein the compressible interlayer consists essentially of a metal or alloy that exhibits solid solubility with the porous tantalum structure and the substrate.

18. The assembly of claim 17 in which the compressible interlayer has a porosity of at least about 5 percent.

19. The assembly of claim 17 wherein the compressible interlayer has a thickness of at least about 0.010 inches.

20. The assembly of claim 17 in which the interlayer consists essentially of at least one of hafnium, manganese, niobium, palladium, zirconium, titanium, or alloys or combinations thereof.

21. A medical implant comprising:

a porous tantalum structure;

a substrate comprising cobalt or cobalt-chromium alloy; and

a compressed interlayer between a surface of the porous tantalum structure and a surface of the substrate, wherein the compressed interlayer consists essentially of a metal or alloy that exhibits solid solubility with the porous tantalum structure and the substrate.

22. The implant of claim 21 in which the compressed interlayer has a porosity.

23. The implant of claim 22 in which the surface of said substrate comprises a geometrically complex surface.