Method for attaching a porous metal layer to a metal substrate

• US 6,945,448 B2
• Filed: 06/06/2003
• Issued: 09/20/2005
• Est. Priority Date: 06/18/2002
• Status: Active Grant

• Current Assignee: Zimmer Incorporated (Zimmer Biomet Holdings, Inc.)
• Original Assignee: Zimmer Technology Incorporated (Zimmer Biomet Holdings, Inc.)
• Inventors: Clarke, William, Swarts, Dale, Charlebois, Steven J., Scrafton, Joel G., Medlin, Dana J., Shetty, H. Ravindranath, Pletcher, Dirk L.
• Primary Examiner(s): Cooke, Colleen P.
• Application Number:
  US10/455,846
• Publication Number:
  US 20030232124A1
• Time in Patent Office: 837 Days
• Field of Search: 228/248.1, 228/245, 228/253, 228/255, 228/249, 228/260, 228/261, 228/262.3, 228/262.31, 228/262.71, 228/262.72, 623/923, 623/920, 623/901, 427/2.24, 427/2.26, 427/455, 427/456, 427/475, 427/528, 427/531, 427/123, 427/124, 427/421, 427/427, 427/430.1, 427/431, 427/432, 427/435, 427/436
• US Class Current: 228/248.1
• CPC Class Codes: A61F 2/30767 Special external or bone-contacting surface, e.g. coating for improving bone ingrowth
• CPC Class Codes: A61F 2/30907 Nets or sleeves applied to surface of prostheses or in cement
• CPC Class Codes: A61F 2/3094 Designing or manufacturing processes
• CPC Class Codes: A61F 2/3859 Femoral components
• CPC Class Codes: A61F 2002/30787 inclined obliquely with respect to each other
• CPC Class Codes: A61F 2002/30967 Diffusion bonding
• CPC Class Codes: A61F 2002/30968 Sintering
• CPC Class Codes: A61F 2002/30978 using electrical discharge machining [EDM]
• CPC Class Codes: A61F 2002/3401 with radial apertures, e.g. radial bores for receiving fixation screws
• CPC Class Codes: A61F 2310/00023 Titanium or titanium-based alloys, e.g. Ti-Ni alloys
• CPC Class Codes: A61F 2310/00029 Cobalt-based alloys, e.g. Co-Cr alloys or Vitallium
• CPC Class Codes: A61F 2310/00407 Coating made of titanium or of Ti-based alloys
• CPC Class Codes: A61F 2310/00544 Coating made of tantalum or Ta-based alloys
• CPC Class Codes: A61L 27/04 Metals or alloys
• CPC Class Codes: A61L 27/30 Inorganic materials
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B22F 7/004 comprising at least one non-porous part
• CPC Class Codes: B22F 7/064 using an intermediate powder layer
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00

Abstract

A method for attaching a porous metal layer to a dense metal substrate, wherein the method is particularly useful in forming orthopedic implants such as femoral knee components or acetabular cups. The method, in one embodiment thereof, comprises providing a structured porous layer; providing a dense metal substrate; providing a binding mixture; applying the binding mixture to the exterior of the substrate; placing the porous layer against the substrate such that the binding mixture is disposed there between forming an assembly; and heat treating the assembly to metallurgically bond the porous layer to the substrate.

Claims

1. A method for attaching a porous metal structure to a metal substrate, the method comprising:

providing a metal substrate comprising a metal selected from the group consisting of cobalt, cobalt alloy, titanium and titanium alloy;

providing a binding mixture;

providing the porous metal structure;

applying the binding mixture to the porous structure by means selected from the group consisting of spraying, and dipping;

placing the porous structure against the substrate such that the binding mixture is disposed between the metal component and the porous structure, thereby forming an assembly; and

heating the assembly to metallurgically bond the porous structure and the substrate.

2. The method of claim 1, wherein the binding mixture comprises a suspending additive selected from the group consisting of gelatin, PVA and water, and wherein the binding mixture further comprises a powdered metal.

3. The method of claim 2, wherein the metal powder is selected from the group consisting of cobalt, cobalt alloy, hafnium, molybdenum, palladium, niobium, zirconium, zirconium alloy, titanium, and titanium alloy.

4. The method of claim 3, wherein the binding mixture comprises above about 10% by volume powdered metal.

5. The method of claim 3, wherein the binding mixture comprises above about 30% by volume powder.

6. The method of claim 3, wherein the binding mixture comprises above about 68% by volume powdered metal.

7. The method of claim 3, wherein the binding mixture comprises about 95% by volume powdered metal.

8. The method of claim 1, wherein the heating step comprises:

heating the assembly at about 100°

C. to 600°

C. for about 1 to 4 hours; and

further heating the assembly at about 800°

C. to 1600°

C. for about 1 hour to about 4 hours.

9. The method of claim 8, wherein the heating step is performed in an inert environment comprising a gas selected from the group consisting of argon and helium.

10. The method of claim 8, wherein the heating step is performed in an at least partial vacuum.

23. The method of any one of claims 1-20, 21 or 22, wherein the step of applying the binding mixture comprises applying the binding mixture to the metal substrate and to the porous metal layer.

11. A method for attaching a porous metal structure to a metal substrate, the method comprising:

providing a metal substrate comprising a metal selected from the group consisting of cobalt, cobalt alloy, titanium and titanium alloy;

providing a binding mixture;

providing the porous metal structure;

applying the binding mixture to the porous structure by means selected from the group consisting of spraying, and dipping;

placing the porous structure against the substrate such that the binding mixture is disposed between the metal component and the porous structure, thereby forming an assembly; and

applying heat and pressure to the assembly to metallurgically bond the porous structure and the substrate.

12. The method of claim 11, wherein the binding mixture comprises a suspending additive selected from the group consisting of gelatin, PVA and water, and wherein the binding mixture further comprises a powdered metal.

13. The method of claim 12, wherein the powdered metal is selected from the group consisting of cobalt, cobalt alloy, hafnium, molybdenum, palladium, niobium, zirconium, zirconium alloy, titanium, and titanium alloy.

14. The method of claim 13, wherein the binding mixture comprises above about 10% by volume powdered metal.

15. The method of claim 13, wherein the binding mixture comprises above about 30% by volume powdered metal.

16. The method of claim 13, wherein the binding mixture comprises above about 68% by volume powdered metal.

17. The method of claim 13, wherein the binding mixture comprises about 95% by volume powdered metal.

18. The method of claim 11, wherein the step of applying heat and pressure comprises:

heating the assembly to about 800°

C. to 1600°

C. for about 1 hour to about 4 hours, at a clamping pressure of between about 200 p.s.i, and 1200 p.s.i.

19. The method of claim 18, wherein the step of applying heat and pressure is performed in an inert environment comprising a gas selected from the group consisting of argon and helium.

20. The method of claim 18, wherein the step of applying heat and pressure is performed in an at least partial vacuum.

21. A method for attaching a porous metal structure to a metal component of an orthopedic implant, the method comprising:

providing a metal component comprising a metal selected from the group consisting of cobalt, cobalt alloy, titanium and titanium alloy, said metal component having a desired shape and a bone contacting surface;

providing a binding mixture;

providing the porous metal structure in a desired shape;

applying the binding mixture to the porous structure by means selected from the group consisting of spraying, and dipping;

placing the porous structure against the bone contacting surface of the metal component such that the binding mixture is disposed between the metal component and the porous structure, thereby forming an assembly; and

heating the assembly to metallurgically bond the porous structure and the metal component.

22. A method for attaching a porous metal structure to a metal component of an orthopedic implant, the method comprising:

providing a metal component comprising a metal selected from the group consisting of cobalt, cobalt alloy, titanium and titanium alloy, said metal component having a desired shape and a bone contacting surface;

providing a binding mixture;

providing the porous metal structure in a desired shape;

applying the binding mixture to the porous structure by means selected from the group consisting of spraying, and dipping;

placing the porous structure against the bone contacting surface of the metal component such that the binding mixture is disposed between the metal component and the porous metal structure, thereby forming an assembly; and

applying heat and pressure to the assembly to metallurgically bond the porous structure and the metal component.