Stent made of a cobalt alloy
AssigneeBIOTRONIK SE & Co. KG
InventorBodo Gerold
Life of this patent
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Abstract
A stent made entirely or partially of a cobalt alloy having the following composition: Co: 18.36-66.85% by weight Cr: 17.0-30.0% by weight Mn: 4.0-10.0% by weight W: 9.0-18.0% by weight Fe: 3.0-20.0% by weight C: 0.03-0.5% by weight N: 0.1-1.0% by weight Si: 0-2.0% by weight O: 0-0.05% by weight with the alloying components and production-related impurities adding up to 100% by weight and (i) a PRE value for corrosion resistance, which is derived from the weight percentages of the alloying components according to formula (1) PRE=[Cr]+1.65×[W]+30×[N] (1) ranges between 34 and 89; and (ii) for the contents of nitrogen and carbon the following restrictions according to formula (2) and (3) apply 0.15≦C+N≦1.00 (2) 0.25≦C+N≦1.00 (3).
Claims15
A stent comprising a filigree support structure made entirely or partially of a nickel-free cobalt alloy comprising a tensile strength of greater than 1000 MPa and having the following composition:
- alloying components comprising:
- Co:
- 18.36-66.85% by weight
- Cr:
- 17.0-30.0% by weight
- Mn:
- 7.0-10.0% by weight
- W:
- 9.0-18.0% by weight
- Fe:
- 3.0-20.0% by weight
- C:
- 0.03-0.5% by weight
- N:
- 0.1-1.0% by weight
- Si:
- 0-2.0% by weight
- O:
- 0-0.05% by weight
- with the alloying components and production-related impurities adding up to 100% by weight;
- (i) a PRE value for corrosion resistance, which is derived from the weight percentages of the alloying components according to formula (1)
- PRE=[Cr]+1.65×[W]+30×[N] (1)
- ranges between 34 and 89;
- and
- (ii) the contents of nitrogen and carbon are restricted according to formula (2)
- 0.15≦C+N≦1.00 (2).
A method of forming a stent comprising:
- a) providing a nickel free cobalt alloy comprising a tensile strength of greater than 1000 MPa and having the composition:
- alloying components comprising:
- Co:
- 18.36-66.85% by weight
- Cr:
- 17.0-30.0% by weight
- Mn:
- 4.0-10.0% by weight
- W:
- 9.0-18.0% by weight
- Fe:
- 3.0-20.0% by weight
- C:
- 0.03-0.5% by weight
- N:
- 0.1-1.0% by weight
- Si:
- 0-2.0% by weight
- O:
- 0-0.05% by weight
- with the alloying components and production-related impurities adding up to 100% by weight;
- (i) a PRE value for corrosion resistance, which is derived from the weight percentages of the alloying components according to formula (1)
- PRE=[Cr]+1.65×[W]+30×[N] (1)
- ranges between 34 and 89;
- (ii) the contents of nitrogen and carbon are restricted according to formula (2)
- 0.15≦C+N≦1.00 (2);
- and
- b) forming a filigree support structure as a stent from the cobalt alloy.
A stent comprising a filigree support structure made entirely or partially of a cobalt alloy comprising a tensile strength of greater than 1000 MPa and having the following composition:
- alloying components comprising:
- Co:
- 18.36-66.85% by weight
- Cr:
- 17.0-30.0% by weight
- Mn:
- 4.0-10.0% by weight
- W:
- 9.0-18.0% by weight
- Fe:
- 7.5-10.5% by weight
- C:
- 0.03-0.5% by weight
- N:
- 0.1-1.0% by weight
- Si:
- 0-2.0% by weight
- O:
- 0-0.05% by weight
- with the alloying components and production-related impurities adding up to 100% by weight;
- (i) a PRE value for corrosion resistance, which is derived from the weight percentages of the alloying components according to formula (1)
- PRE=[Cr]+1.65×[W]+30×[N] (1)
- ranges between 34 and 89;
- and
- (ii) the contents of nitrogen and carbon are restricted according to
- 0.15≦C+N≦1.00 (2).
Dependencies are inferred from the claim text.