Metal alloy for a stent
View Patent ↗A stent that is at least partially formed of a novel metal alloy, which novel metal alloy improves the physical properties of the stent.
1. A medical device at least partially formed of a metal alloy which improves the strength and radiopacity of the medical device, said metal alloy including at least about 95 weight percent of a solid solution of at least three metals selected from the group consisting of rhenium, molybdenum, titanium, yttrium, and zirconium, said metal alloy including 40-55 weight percent rhenium and 45-60 weight percent molybdenum, said metal alloy including carbon, nitrogen and oxygen, said metal alloy having a nitrogen content of less than about 20 ppm, a carbon content of less than about 150 ppm, and an oxygen content of less than about 75 ppm, said metal alloy having a carbon to oxygen atomic ratio of at least about 1:1, said metal alloy having a carbon to oxygen atomic ratio of less than about 50:1.
2. The medical device as defined in claim 1 , wherein said metal alloy has an average yield strength of at least about 90 ksi and an average ultimate tensile strength of at least about 95 ksi, said metal alloy having an average grain size of over 5 ASTM, and said metal alloy having an average tensile elongation of at least about 25%.
3. The medical device as defined in claim 1 , wherein said metal alloy has an average density of at least 12.5 gm/cc.
4. The medical device as defined in claim 2 , wherein said metal alloy has an average density of at least 12.5 gm/cc.
5. The medical device as defined in claim 1 , wherein said metal alloy includes a plurality of second phase particles, said second phase particles including carbides, carbo-nitrides, oxides or mixtures thereof, said metal alloy having a carbon to oxygen atomic ratio of at least about 2:1.
6. The medical device as defined in claim 4 , wherein said metal alloy includes a plurality of second phase particles, said second phase particles including carbides, carbo-nitrides, oxides or mixtures thereof, said metal alloy having a carbon to oxygen atomic ratio of at least about 2:1.
7. The medical device as defined in claim 1 , wherein said metal alloy including at least about 99 weight percent of a solid solution of at least three metals selected from the group consisting of rhenium, molybdenum, titanium, yttrium, and zirconium.
8. The medical device as defined in claim 7 , said metal alloy including at least about 99.95 weight percent of a solid solution of at least three metals selected from the group consisting of rhenium, molybdenum, titanium, yttrium, and zirconium.
9. The medical device as defined in claim 1 , wherein said metal alloy includes about 46-49 weight percent rhenium and about 51-54 weight percent molybdenum.
10. The medical device as defined in claim 1 , wherein said metal alloy includes at least about 99.5 weight percent rhenium and molybdenum.
11. The medical device as defined in claim 8 , wherein said metal alloy includes at least about 99.5 weight percent rhenium and molybdenum.
12. The medical device as defined in claim 1 , wherein said carbon content of said metal alloy is less than about 100 ppm and said oxygen content of said metal alloy is less than about 50 ppm.
13. The medical device as defined in claim 11 , wherein said carbon content of said metal alloy is less than about 100 ppm and said oxygen content of said metal alloy is less than about 50 ppm.
14. The medical device as defined in claim 12 , wherein said carbon content of said metal alloy is less than about 50 ppm and said oxygen content of said metal alloy is less than about 10 ppm.
15. The medical device as defined in claim 1 , wherein said atomic ratio of carbon to oxygen in said metal alloy is up to about 50:1.
16. The medical device as defined in claim 13 , wherein said atomic ratio of carbon to oxygen in said metal alloy is up to about 50:1.
17. The medical device as defined in claim 1 , wherein said nitrogen content of said metal alloy is less than about 10 ppm.
18. The medical device as defined in claim 16 , wherein said nitrogen content of said metal alloy is less than about 10 ppm.
19. The medical device as defined in claim 1 , wherein said metal alloy has an average grain size of about 5-10 ASTM.
20. The medical device as defined in claim 18 , wherein said metal alloy has an average grain size of about 5-10 ASTM.
21. The medical device as defined in claim 1 , wherein said metal alloy includes titanium, said titanium content is less than 1 weight percent of said metal alloy.
22. The medical device as defined in claim 20 , wherein said metal alloy includes titanium, said titanium content is less than 1 weight percent of said metal alloy.
23. The medical device as defined in claim 1 , wherein said metal alloy includes yttrium, said yttrium content is less than about 0.3 weight percent of said metal alloy.
24. The medical device as defined in claim 20 , wherein said metal alloy includes yttrium, said yttrium content is less than about 0.3 weight percent of said metal alloy.
25. The medical device as defined in claim 1 , wherein said metal alloy includes zirconium, said zirconium content is less than about 0.5 weight percent of said metal alloy.
26. The medical device as defined in claim 20 , wherein said metal alloy includes zirconium, said zirconium content is less than about 0.5 weight percent of said metal alloy.
27. The medical device as defined in claim 1 , wherein said metal alloy includes titanium and zirconium, said titanium and zirconium having a weight ratio of about 1-10:1.
28. The medical device as defined in claim 20 , wherein said metal alloy includes titanium and zirconium, said titanium and zirconium having a weight ratio of about 1-10:1.
29. The medical device as defined in claim 27 , wherein said metal alloy includes titanium and zirconium, said titanium and zirconium having a weight ratio of about 1.2-5:1.
30. The medical device as defined in claim 1 , wherein said medical device is a stent, graft, valve, screw, nail, rod, PFO device, prosthetic device, sheath, guide wire, balloon catheter, hypotube, catheter, electrophysiology catheter, staple or cutting device.
31. The medical device as defined in claim 1 , wherein said metal alloy comprises by weight percent:
C
<150 ppm
Mo
50-55%
O
<100 ppm
N
<40 ppm
Re
up to 55%
Ti
≦0.5%
Y
≦0.1%
Zr
≦0.25%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
32. The medical device as defined in claim 20 , wherein said metal alloy comprises by weight percent:
C
<150 ppm
Mo
50-55%
O
<100 ppm
N
<40 ppm
Re
up to 55%
Ti
≦0.5%
Y
≦0.1%
Zr
≦0.25%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
33. The medical device as defined in claim 1 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
50-60%
O
<20 ppm
N
<20 ppm
Re
40-50%
Ti
≦0.4%
Y
≦0.1%
Zr
≦0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
34. The medical device as defined in claim 20 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
50-55%
O
<20 ppm
N
<20 ppm
Re
45-50%
Ti
≦0.4%
Y
≦0.1%
Zr
≦0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
35. The medical device as defined in claim 1 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
50-55.5%
O
<20 ppm
N
<20 ppm
Re
up to 50%
Ti
≦0.4%
Y
≦0.1%
Zr
≦0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
36. The medical device as defined in claim 20 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
50-55.5%
O
<20 ppm
N
<20 ppm
Re
up to 50%
Ti
≦0.4%
Y
≦0.1%
Zr
≦0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent.
37. The medical device as defined in claim 1 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
52-56%
O
<10 ppm
N
<10 ppm
Re
up to 48%
Ti
0.2-0.4%
Y
0-0.08%
Zr
0-0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent said average yield strength at least about 110 ksi.
38. The medical device as defined in claim 20 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
52-56%
O
<10 ppm
N
<10 ppm
Re
up to 48%
Ti
0.2-0.4%
Y
0-0.08%
Zr
0-0.2%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent said average yield strength at least about 110 ksi.
39. The medical device as defined in claim 1 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
52.5-55%
O
<10 ppm
N
<10 ppm
Re
45-47.5%
Ti
0.3-0.4%
Y
0.005-0.05%
Zr
0.1-0.25%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent said average yield strength at least about 110 ksi.
40. The medical device as defined in claim 20 , wherein said metal alloy comprises by weight percent:
C
<50 ppm
Mo
52.5-55%
O
<10 ppm
N
<10 ppm
Re
45-47.5%
Ti
0.3-0.4%
Y
0.005-0.05%
Zr
0.1-0.25%
and has a grain size of at least 5 ASTM, an average tensile elongation of at least 25%, and said content of rhenium plus molybdenum plus metal component is at least about 99.5 weight percent said average yield strength at least about 110 ksi.
41. A medical device at least partially formed of a metal alloy which improves the strength and radiopacity of the medical device, said metal alloy including at least about 95 weight percent of a solid solution of at least three metals selected from the group consisting of rhenium, molybdenum, titanium, yttrium, and zirconium, said metal alloy including at least 40 weight percent rhenium and at least 40 weight percent molybdenum, said metal alloy including carbon, nitrogen and oxygen, said metal alloy having a nitrogen content of less than about 30 ppm, a carbon content of up to 200 ppm, and an oxygen content of up to 100 ppm, said metal alloy having a carbon to oxygen atomic ratio of at least about 1:1, said metal alloy having a carbon to oxygen atomic ratio of less than about 50:1, said metal alloy having an average yield strength of at least about 70 ksi and an average ultimate tensile strength of about 80-150 ksi, said metal alloy having an average grain size of over 5 ASTM, and said metal alloy having an average tensile elongation of at least about 25%.
42. A stent that is formed of at least about 80 weight percent of a metal alloy which improves the strength and radiopacity of the stent, said metal alloy including at least about 99.9 weight percent of a solid solution of rhenium, molybdenum and an additional metal, said metal alloy including at least and effective amount and up to about 0.5 weight percent of said additional metal, said additional metal including a metal selected from the group consisting of titanium, yttrium, and zirconium, said metal alloy including 45-55 weight percent rhenium and 45-60 weight percent molybdenum, said metal alloy including carbon and oxygen and having a carbon to oxygen atomic ratio of at least about 2.5:1, said metal alloy having an average yield strength of at least about 110 ksi and an average ultimate tensile strength of about 100-150 ksi, said metal alloy having an average grain size of about 6-9 ASTM, said metal alloy having an average tensile elongation of about 25-35%, said metal alloy having an average density of at least about 13.5 gm/cm.
43. The stent as defined in claim 42 , wherein said metal alloy including by weight percent:
C
≦50 ppm
Mo
52-56%
O
≦20 ppm
N
≦10 ppm
Re
44-48%
Ti
0-0.4%
Y
0-0.08%
Zr
0-0.25%.
44. The stent as defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦50 ppm
Mo
52.5-55%
O
≦10 ppm
N
≦10 ppm
Re
45-47.5%
Ti
0.3-0.4%
Y
0.005-0.05%
Zr
0.1-0.25%
and a weight ratio of titanium to zirconium is about 1.5-3:1.
45. The stent as defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦40 ppm
Mo
51-53%
O
≦15 ppm
N
≦10 ppm
Re
47-49%
Ti
0.1-0.35%
Y
0%
Zr
0%.
46. The stent defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦40 ppm
Mo
51.5-54%
O
≦15 ppm
N
≦10 ppm
Re
46-48.5%
Ti
%0
Y
0.002-0.08%
Zr
%0.
47. The stent defined in claim 42 , wherein said metal alloy comprises by percent:
C
≦40 ppm
Mo
52-55%
O
≦15 ppm
N
≦10 ppm
Re
45-48%
Ti
%0
Y
%0
Zr
0.01-0.2%.
48. The stent defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦40 ppm
Mo
52.5-55%
O
≦10 ppm
N
≦10 ppm
Re
45-47.5%
Ti
0.1-0.3%
Y
%0
Zr
0.05-0.15%
and a weight ratio of titanium to zirconium is about 1.5-3:1.
49. The stent as defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦40 ppm
Mo
52-55%
O
≦10 ppm
N
≦10 ppm
Re
45-49%
Ti
0.05-0.4%
Y
0.005-0.07%
Zr
0%.
50. The stent as defined in claim 42 , wherein said metal alloy comprises by weight percent:
C
≦40 ppm
Mo
52.5-55.5%
O
≦10 ppm
N
≦10 ppm
Re
44.5-47.5%
Ti
%0
Y
0.004-0.06%
Zr
0.1-0.2%.