Applications of diffusion hardening techniques

1. A device, comprising:

a first portion, said first portion having a first contacting surface;

a second portion, said second portion having a second contacting surface;

wherein the first portion and the second portion are comprised of metal or metal alloy, and wherein the first and second contacting surfaces contact one another; and

wherein one of conditions (a) and (b) is met:

(a) one of said first and second contacting surfaces comprises a diffusion hardened metallic surface which is diffusion hardened with a diffusion hardening species and the other of said first and second contacting surfaces is a metallic surface that is not diffusion hardened;

(b) both of said first and second contacting surfaces comprise a diffusion hardened metallic surface wherein said first contacting surface is diffusion hardened with at least a first diffusion hardening species and said second contacting surface is diffusion hardened with at least a second diffusion hardening species and wherein said first diffusion hardening species is different from said second diffusion hardening species;

wherein said diffusion hardening species is selected from the group consisting of carbon, nitrogen, oxygen, boron, and any combination thereof; and

wherein said device is a medical implant.

2. The device of claim 1 , wherein said metal or metal alloy comprising said first portion is different from said metal or metal alloy comprising said second portion.

3. The device of claim 1 , wherein said metal or metal alloy is cobalt chrome.

4. The device of claim 1 , wherein one or both of said contacting surfaces comprises a plasma hardened surface.

5. The device of claim 4 , wherein said plasma hardened surface is selected from the group consisting of a plasma carburized surface, a plasma nitrided surface, a plasma oxidized surface, a plasma bonded surface and any combination thereof.

6. The device of claim 1 , wherein said medical implant is a hip implant.

7. The device of claim 6 , wherein one of said first portion and second portion is a femoral component comprising a femoral head and wherein said femoral head comprises a contacting surface; and

wherein the other of said first portion and second portion is an acetabular component, said acetabular component comprising an inner surface wherein said inner surface comprises a contacting surface.

8. The device of claim 7 , wherein one or both of said contacting surfaces comprises a plasma hardened surface.

9. The device of claim 8 , wherein said plasma hardened surface is selected from the group consisting of a plasma carburized surface, a plasma nitrided surface, a plasma oxidized surface, a plasma bonded surface and any combination thereof.

10. The device of claim 1 , wherein said medical implant is a knee implant.

11. The device of claim 10 , wherein one of said first portion and second portion is a femoral component comprising at least one condyle, said at least one condyle comprising a contacting surface, and wherein the other of said first portion and second portion is a tibial component, said tibial component comprising a contacting surface.

12. The device of claim 11 , wherein one or both of said contacting surfaces comprises a plasma hardened surface.

13. The device of claim 12 , wherein said plasma hardened surface is selected from the group consisting of a plasma carburized surface, a plasma nitrided surface, a plasma oxidized surface, a plasma bonded surface and any combination thereof.

14. The device of claim 1 , wherein said medical implant is selected from the group consisting of a shoulder implant, an elbow implant, a finger implant, a vertebral implant, and a tempro-mandibular implant.

15. The device of claim 1 , wherein said first contacting surface and said second contacting surface articulate against one another.

16. The device of claim 1 , further comprising a deposited ceramic coating on one or both of said first and second contacting surfaces.

17. The device of claim 16 , wherein said deposited ceramic coating is selected from the group consisting of ceramic oxides, ceramic nitrides, ceramic carbides, ceramic borides, and any combination thereof.

18. The device of claim 1 , further comprising a diamond or diamond-like carbon coating on one or both of said first and second contacting surfaces.

19. The device of claim 1 , wherein both of said first and second contacting surfaces comprise a diffusion hardened metallic surface and wherein said first contacting surface is diffusion carburized and diffusion oxidized, and said second contacting surface is diffusion carburized.

20. The device of claim 1 , wherein condition (b) applies, and

wherein said diffusion hardening species for said first contacting surface is selected from the group consisting of carbon, nitrogen, boron, and any combination thereof; and

wherein said diffusion hardening species for said second contacting surface is selected from the group consisting of carbon, nitrogen, oxygen, boron, and any combination thereof; and

subject to the condition that one of said contacting surfaces is diffusion hardened with a diffusion hardening species that is not present as a diffusion hardening species in the other contacting surface.

21. The device of claim 1 , wherein said diffusion hardening species is selected from the group consisting of carbon, nitrogen, oxygen, and any combination thereof.

22. The device of claim 1 , wherein said first contacting surface comprises a first articulating surface;

wherein said second contacting surface comprises a second articulating surface, and wherein said first articulating surface is configured to articulate with said second articulating surface.

23. The device of claim 1 , wherein said first portion and said second portion are formed of different materials.

24. The device of claim 1 , wherein one of said first and second portions comprises an acetabular cup, and wherein the other of said first and second portions comprises a femoral component.