Passivation of nitinol wire for vascular implants - A demonstration of the benefits

B. O'Brien; W. M. Carroll; M. J. Kelly

doi:10.1016/S0142-9612(01)00299-X

Passivation of nitinol wire for vascular implants - A demonstration of the benefits

B. O'Brien, W. M. Carroll, M. J. Kelly

Research output: Contribution to a Journal (Peer & Non Peer) › Article › peer-review

159 Citations (Scopus)

Abstract

This study investigated a passivation process for polished nitinol wires and vascular stent components, after being given a typical shape setting heat treatment. Heat treated samples were passivated in a nitric acid solution and a series of corrosion tests, surface analysis and chemical analysis was performed. Potentiodynamic polarization tests demonstrated a significant increase in breakdown potential for passivated samples, compared to heat treated surfaces. Surface analysis indicated that the passivation reduces Ni and NiO content in the oxide and increases TiO₂ content. Chemical analysis of passivation solutions suggests that the improvement in corrosion resistance is proportional to the quantity of nickel removed. Long term immersion tests demonstrate that nickel release from the surface of the material decreases with time and the quantity of nickel released is lower for passivated samples. The improved corrosion resistance is maintained after extended periods of immersion in saline solution.

Original language	English
Pages (from-to)	1739-1748
Number of pages	10
Journal	Biomaterials
Volume	23
Issue number	8
DOIs	https://doi.org/10.1016/S0142-9612(01)00299-X
Publication status	Published - 15 Apr 2002
Externally published	Yes

Keywords

Corrosion
Implants
NiTi
Passivation

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10.1016/S0142-9612(01)00299-X

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title = "Passivation of nitinol wire for vascular implants - A demonstration of the benefits",

abstract = "This study investigated a passivation process for polished nitinol wires and vascular stent components, after being given a typical shape setting heat treatment. Heat treated samples were passivated in a nitric acid solution and a series of corrosion tests, surface analysis and chemical analysis was performed. Potentiodynamic polarization tests demonstrated a significant increase in breakdown potential for passivated samples, compared to heat treated surfaces. Surface analysis indicated that the passivation reduces Ni and NiO content in the oxide and increases TiO2 content. Chemical analysis of passivation solutions suggests that the improvement in corrosion resistance is proportional to the quantity of nickel removed. Long term immersion tests demonstrate that nickel release from the surface of the material decreases with time and the quantity of nickel released is lower for passivated samples. The improved corrosion resistance is maintained after extended periods of immersion in saline solution.",

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AU - O'Brien, B.

AU - Carroll, W. M.

AU - Kelly, M. J.

PY - 2002/4/15

Y1 - 2002/4/15

N2 - This study investigated a passivation process for polished nitinol wires and vascular stent components, after being given a typical shape setting heat treatment. Heat treated samples were passivated in a nitric acid solution and a series of corrosion tests, surface analysis and chemical analysis was performed. Potentiodynamic polarization tests demonstrated a significant increase in breakdown potential for passivated samples, compared to heat treated surfaces. Surface analysis indicated that the passivation reduces Ni and NiO content in the oxide and increases TiO2 content. Chemical analysis of passivation solutions suggests that the improvement in corrosion resistance is proportional to the quantity of nickel removed. Long term immersion tests demonstrate that nickel release from the surface of the material decreases with time and the quantity of nickel released is lower for passivated samples. The improved corrosion resistance is maintained after extended periods of immersion in saline solution.

AB - This study investigated a passivation process for polished nitinol wires and vascular stent components, after being given a typical shape setting heat treatment. Heat treated samples were passivated in a nitric acid solution and a series of corrosion tests, surface analysis and chemical analysis was performed. Potentiodynamic polarization tests demonstrated a significant increase in breakdown potential for passivated samples, compared to heat treated surfaces. Surface analysis indicated that the passivation reduces Ni and NiO content in the oxide and increases TiO2 content. Chemical analysis of passivation solutions suggests that the improvement in corrosion resistance is proportional to the quantity of nickel removed. Long term immersion tests demonstrate that nickel release from the surface of the material decreases with time and the quantity of nickel released is lower for passivated samples. The improved corrosion resistance is maintained after extended periods of immersion in saline solution.

KW - Corrosion

KW - Implants

KW - NiTi

KW - Passivation

UR - https://www.scopus.com/pages/publications/0037089606

U2 - 10.1016/S0142-9612(01)00299-X

DO - 10.1016/S0142-9612(01)00299-X

M3 - Article

SN - 0142-9612

VL - 23

SP - 1739

EP - 1748

JO - Biomaterials

JF - Biomaterials

IS - 8

ER -

Passivation of nitinol wire for vascular implants - A demonstration of the benefits

Abstract

Keywords

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