Coating for a CoCrMo substrate
View Patent ↗A coating for a CoCrMo substrate including a first layer located directly on the substrate and including Ta(CoCrMo) 0.5-2.0 , a second layer located directly on the first layer and including tantalum, a third layer located directly on the second layer and including tantalum carbide, and a fourth layer located directly on the third layer and including diamond-like carbon (DLC).
1. A coating for a CoCrMo substrate comprising:
a first layer comprising Ta(CoCrMo) 0.5-2.0 ;
a second layer comprising amorphous alpha-tantalum and nanocrystalline alpha-tantalum;
a third layer comprising tantalum carbide; and
a fourth layer comprising diamond-like carbon (DLC),
wherein the coating contains no beta-tantalum.
2. The coating according to claim 1 , wherein the first layer has a thickness of about 1 nm to about 5 nm.
3. The coating according to claim 1 , wherein the second layer has a thickness of at least 20 nm.
4. The coating according to claim 1 , wherein the third layer has a thickness of at least 0.5 nm.
5. The coating according to claim 1 , wherein the fourth layer has a thickness of at least 200 nm.
6. The coating according to claim 1 , wherein the fourth layer has a hydrogen content of less than 35 atomic %.
7. The coating according to claim 1 , wherein the first layer, the second layer, and the third layer each has an oxygen content lower than 5 atomic %.
8. The coating according to claim 1 , wherein the coating has a mean roughness R a below 50 nm.
9. The coating according to claim 1 , wherein the coating has a maximum roughness R t below 200 nm.
10. The coating according to claim 1 , wherein total thickness of all four layers is in the range of about 0.5 μm to about 10 μm.
11. The coating according to claim 1 , wherein the second layer is doped with tungsten, niobium or titanium.
12. A device comprising a substrate with a coating according to claim 1 .
13. The device according to claim 12 , wherein said coating is penetrated by a hole reaching the substrate.
14. The device according to claim 13 , wherein said hole has a diameter d≦10 micrometers.
15. The device according to claim 12 , wherein the device is a joint prosthesis.
16. The coating according to claim 1 , wherein the second layer consists essentially of amorphous alpha tantalum and nanocrystalline alpha tantalum.
17. A coating for a CoCrMo substrate comprising:
a first layer comprising Ta(CoCrMo) 0.5-2.0 ;
a second layer comprising amorphous alpha-tantalum and nanocrystalline alpha-tantalum;
a third layer comprising tantalum carbide; and
a fourth layer comprising diamond-like carbon (DLC).
18. The coating according to claim 17 , wherein the second layer consists essentially of amorphous alpha tantalum and nanocrystalline alpha tantalum.
19. The coating according to claim 17 , wherein the second layer is essentially free of beta tantalum.
20. The coating according to claim 17 , wherein the first layer has a thickness of 1 nm to 5 nm, the second layer has a thickness of 20 nm to 1000 nm, and the third layer has a thickness of about 0.5 nm to 10 nm.