Applications of diffusion hardening techniques
A device, for example a medical implant, and a method of making the same, the device having a metal or metal alloy substrate, for example cobalt chrome, and a diffusion hardened metallic surface, for example a plasma carburized surface, contacting a non-diffusion hardened surface or a diffusion hardened surface having a diffusion hardening species different from that of the opposing surface.
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 a deposited ceramic coating on one or both of said first and second contacting surfaces, 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.
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 one or both of said contacting surfaces comprises a plasma hardened surface.
4. The device of claim 1 , wherein said device is a hip implant, 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.
5. The device of claim 1 , wherein said device is a knee implant, 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.
6. The device of claim 1 , wherein said first contacting surface and said second contacting surface articulate against one another.
7. The device of claim 1 , wherein said deposited ceramic coating is selected from the group consisting of ceramic oxides, ceramic nitrides, ceramic carbides, ceramic borides, and any combination thereof.
8. 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.
9. 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.
10. 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 articulate against 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 first portion and said second portion are formed of different materials.
11. The device of claim 10 , wherein one or both of said contacting surfaces comprises a plasma hardened surface.
12. The device of claim 10 , wherein the device is a hip implant, 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.
13. The device of claim 10 , wherein said device is a knee implant, 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.
14. The device of claim 10 , 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.
15. The device of claim 10 , 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.
16. 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 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;
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; and
wherein said diffusion hardening species is selected from the group consisting of carbon, nitrogen, oxygen, boron, and any combination thereof.
17. The device of claim 16 , wherein said metal or metal alloy comprising said first portion is different from said metal or metal alloy comprising said second portion.
18. The device of claim 16 , wherein one or both of said contacting surfaces comprises a plasma hardened surface.
19. The device of claim 16 , wherein said first contacting surface and said second contacting surface articulate against one another.
20. The device of claim 16 , 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.
21. The device of claim 16 , 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.