Stainless steel alloy having lowered nickel chromium toxicity and improved biocompatibility

• US 7,445,749 B2
• Filed: 01/28/2003
• Issued: 11/04/2008
• Est. Priority Date: 05/11/2001
• Status: Expired due to Term

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Craig, Charles Horace
• Primary Examiner(s): Sheehan; John P.
• Assistant Examiner(s): ROE, JESSEE RANDALL
• Application Number:
  US10/352,458
• Publication Number:
  US 20030194343A1
• Time in Patent Office: 2,107 Days
• Field of Search: 420/584.1, 420/583, 420/43, 420/34, 420/35, 148/325, 148/327, 148335-333, 606/198
• US Class Current: 420/35
• CPC Class Codes: A61L 31/022 Metals or alloys
• CPC Class Codes: C22C 38/002 containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
• CPC Class Codes: C22C 38/44 with molybdenum or tungsten
• CPC Class Codes: C22C 38/48 with niobium or tantalum

Abstract

The present invention is directed towards an austenitic, stainless steel series 300 alloy having improved biocompatible characteristics. The modified stainless steel alloy consists essentially of, in weight percent, about

CMnSiPS≦0.030≦2.00≦0.750≦0.023≦0.010CrMoNiFe“X”8.5-11.50.0-6.256.5-7.546.185-74.0005.0-10.0
whereby variable “x” could be comprised from a group consisting of Gold, Osmium, Palladium, Platinum, Rhenium, Tantalum, or Tungsten. The alloy provides a unique combination of strength, ductility, corrosion resistance, and other mechanical properties which also has improved biocompatible characteristics.

Claims

1. A stent, comprising:

a member capable of supporting a body passageway, the member being formed of a non-magnetic, austenitic steel alloy comprising

between about 8.5 and 11.5 weight percent of chromium,

between about 2.0 and about 10 weight percent of a first element selected from the group consisting of gold, osmium, palladium, platinum, and rhenium, and

iron.

2. The stent of claim 1, wherein the alloy further comprises less than 7.5 weight percent of nickel.

3. The stent of claim 1, wherein the alloy further comprises between about 6.5 and 7.5 weight percent of nickel.

4. The stent of claim 1, wherein the first element is platinum.

5. The stent of claim 1, wherein the alloy comprises between about 5 and about 10 weight percent of the first element.

6. The stent of claim 1, wherein the alloy comprises a combination of first elements.

7. The stent of claim 1, wherein the alloy further comprises molybdenum.

8. The stent of claim 7, wherein the alloy comprises less than about 6.25 weight percent of molybdenum.

9. The stent of claim 1, wherein the alloy further comprises manganese.

10. The stent of claim 9, wherein the alloy comprises less than about 2 weight percent of manganese.

11. A stent, comprising:

a member capable of supporting a body passageway, the member being formed of a non-magnetic, austenitic alloy comprising iron, chromium, a first element selected from the group consisting of gold, osmium, palladium, platinum, and rhenium, and between about 6.5 and 7.5 weight percent nickel, the total amount of chromium and nickel being present at less than about 19 weight percent.

12. The stent of claim 11, wherein the total amount of chromium and nickel is less about 18 weight percent.

13. The stent of claim 11, wherein the total amount of chromium and nickel is less than about 16 weight percent.

14. The stent of claim 11, wherein the alloy comprises more than about 8.5 weight percent of chromium.

15. The stent of claim 11, wherein the alloy comprises between about 8.5 and about 11.5 weight percent of chromium.

16. The stent of claim 11, wherein the first element is platinum.

17. The stent of claim 11, wherein the alloy comprises less than about 10 weight percent of the first element.

18. The stent of claim 16, wherein the alloy comprises between about 5 and about 10 weight percent of the first elements.

19. The stent of claim 16, wherein the alloy comprises a combination of first elements.

20. The stent of claim 11, wherein the alloy further comprises molybdenum.

21. The stent of claim 20, wherein the alloy comprises less than about 6.25 weight percent of molybdenum.

22. The stent of claim 11, wherein the alloy further comprises manganese.

23. The stent of claim 22, wherein the alloy comprises less than about 2 weight percent of manganese.

24. A stent, comprising:

a member capable of supporting a body passageway, the member being formed of a non-magnetic, austenitic alloy comprising

between about 8.5 and 1.5 weight percent of chromium,

between about 6.5 and 7.5 weight percent of nickel,

a first element selected from the group consisting of gold, osmium, palladium, platinum, and rhenium, and

greater than about 46 weight percent of iron.

25. The stent of claim 24, wherein the first element is platinum.

26. The stent of claim 24, wherein the alloy comprises less than about 10 weight percent of the first element.

27. The stent of claim 24, wherein the alloy comprises between about 5 and about 10 weight percent of the first element.

28. The stent of claim 24, wherein the alloy comprises a combination of first elements.

29. The stent of claim 24, wherein the alloy further comprises molybdenum.

30. The stent of claim 29, wherein the alloy comprises less than about 6.25 weight percent of molybdenum.

31. The stent of claim 24, wherein the alloy further comprises manganese.

32. The stent of claim 31, wherein the alloy comprises less than about 2 weight percent of manganese.