STAINLESS STEEL ALLOY HAVING LOWERED NICKEL-CHROMINUM TOXICITY AND IMPROVED BIOCOMPATIBILITY

• US 20080281401A1
• Filed: 07/16/2008
• Published: 11/13/2008
• Est. Priority Date: 05/11/2001
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Craig, Charles Horace
• Granted Patent: US 8,580,189 B2
• Time in Patent Office: Days
• US Class Current: 623/1.15
• 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

1-39. -39. (canceled)

40. A medical implant, comprising:

a member formed of a non-magnetic, austenitic steel alloy comprising

chromium,

2.0 weight percent or greater of a first element selected from the group consisting of gold, osmium, palladium, platinum, rhenium, and tantalum, and

iron.

41. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises between 2.0 weight percent and 10.0 weight percent of the first element.

42. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises between 4.0 weight percent and 5.0 weight percent of the first element.

43. The medical implant of claim 40, wherein the first element is platinum.

44. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises 8.5 weight percent or greater of chromium.

45. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises nickel.

46. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises between 13 weight percent and 15 weight percent nickel.

47. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises less than 3 weight percent molybdenum.

48. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises up to 2.0 weight percent manganese.

49. The medical implant of claim 40, wherein the non-magnetic, austenitic steel alloy comprises between about 46 weight percent and 74 weight percent iron.

50. The medical implant of claim 40, where in the medical implant is an endoprosthesis comprising a member capable of supporting a body passageway, the member being formed of the non-magnetic, austenitic steel alloy.

51. A medical implant, comprising:

a member formed of a non-magnetic, austenitic steel alloy comprising

between 13 and 15 weight percent of nickel,

2.0 weight percent or greater of a first element selected from the group consisting of gold, osmium, palladium, platinum, rhenium, tantalum, and tungsten, and

about 46 weight percent or greater of iron.

52. The medical implant of claim 51, wherein the non-magnetic, austenitic steel alloy comprises between 2.0 weight percent and 10.0 weight percent of the first element.

53. The medical implant of claim 51, wherein the first element is platinum.

54. The medical implant of claim 51, wherein the non-magnetic, austenitic steel alloy comprises greater than 8.5 weight percent chromium.

55. The medical implant of claim 51, wherein the non-magnetic, austenitic steel alloy comprises between about 46 weight percent and 74 weight percent iron.

56. The medical implant of claim 51, where in the medical implant is an endoprosthesis comprising a member capable of supporting a body passageway, the member being formed of the non-magnetic, austenitic steel alloy.

57. The medical implant of claim 51, wherein the medical implant is a stent.

58. A stent, comprising:

a member capable of supporting a body passageway, the member being formed of a non-magnetic, austenitic alloy comprising iron, chromium, 2.0 weight percent or greater of a first element selected from the group consisting of gold, osmium, palladium, platinum, rhenium, and tantalum, the total amount of chromium and nickel being present at less than about 19 weight percent.

59. The stent of claim 58, wherein the first element is platinum.