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Conference Paper: Improved corrosion resistance of plasma carbon coated NiTi orthopedic materials

TitleImproved corrosion resistance of plasma carbon coated NiTi orthopedic materials
Authors
Issue Date2004
PublisherIEEE.
Citation
The 31st IEEE International Conference on Plasma Science, Baltimore, Maryland, USA, 28 June - 1 July 2004, p. 351 How to Cite?
AbstractNickel titanium (NiTi) alloys are useful in orthopedic applications because of their super-elastic properties and shape memory effects. However, when NiTi is used for a prolonged period of time, harmful Ni ions can leach out into the surrounding body fluid inside a human body, and so it is important to design a method to impede the out-diffusion of nickel from the materials into the biological medium. We aim at producing a barrier to mitigate the release of Ni ions during normal use. Carbon coatings have been shown to possess excellent bio-compatibility and good mechanical strength. In this work, amorphous hydrogenated DLC films with a graded C/NiTi interface were fabricated by plasma immersion ion implantation & deposition (PU & D) to provide such a barrier layer on NiTi. The elemental depth profiles and film thickness were determined by X-ray photoelectron spectroscopy (XPS) whereas the surface morphology was evaluated using atomic force microscopy (AFM). The film structure was studied by X-ray diffraction (XRD) and Raman spectroscopy. The corrosion resistance of the film was investigated using electrochemical tests based on ASTM G5-94. Compared to the control sample, the corrosion potential of the sample with the carbon coating changes from -250 to -50 mV and the film breakdown potential increases from 250 to 1200 mV. The corrosion current also diminishes from 10-6 to 10-7 A. The simulated body fluid (SBF) solutions after the electrochemical test were analyzed for Ni concentrations by inductively-coupled plasma mass spectrometry (ICPMS) and that data show that a much smaller amount of Ni has been released from the treated sample surface compared to the untreated control sample surface. Our results thus indicate that the deposited DLC film is effective in retarding the release of Ni ions from the bulk materials and more superior corrosion resistance is achieved based on our tests in a simulated fluid medium and at human body temperature.
Persistent Identifierhttp://hdl.handle.net/10722/46939
ISSN

 

DC FieldValueLanguage
dc.contributor.authorPoon, RWYen_HK
dc.contributor.authorLiu, XYen_HK
dc.contributor.authorChung, CYen_HK
dc.contributor.authorChu, PKen_HK
dc.contributor.authorYeung, KWKen_HK
dc.contributor.authorLu, WWen_HK
dc.contributor.authorCheung, KMCen_HK
dc.date.accessioned2007-10-30T07:01:51Z-
dc.date.available2007-10-30T07:01:51Z-
dc.date.issued2004en_HK
dc.identifier.citationThe 31st IEEE International Conference on Plasma Science, Baltimore, Maryland, USA, 28 June - 1 July 2004, p. 351en_HK
dc.identifier.issn0730-9244en_HK
dc.identifier.urihttp://hdl.handle.net/10722/46939-
dc.description.abstractNickel titanium (NiTi) alloys are useful in orthopedic applications because of their super-elastic properties and shape memory effects. However, when NiTi is used for a prolonged period of time, harmful Ni ions can leach out into the surrounding body fluid inside a human body, and so it is important to design a method to impede the out-diffusion of nickel from the materials into the biological medium. We aim at producing a barrier to mitigate the release of Ni ions during normal use. Carbon coatings have been shown to possess excellent bio-compatibility and good mechanical strength. In this work, amorphous hydrogenated DLC films with a graded C/NiTi interface were fabricated by plasma immersion ion implantation & deposition (PU & D) to provide such a barrier layer on NiTi. The elemental depth profiles and film thickness were determined by X-ray photoelectron spectroscopy (XPS) whereas the surface morphology was evaluated using atomic force microscopy (AFM). The film structure was studied by X-ray diffraction (XRD) and Raman spectroscopy. The corrosion resistance of the film was investigated using electrochemical tests based on ASTM G5-94. Compared to the control sample, the corrosion potential of the sample with the carbon coating changes from -250 to -50 mV and the film breakdown potential increases from 250 to 1200 mV. The corrosion current also diminishes from 10-6 to 10-7 A. The simulated body fluid (SBF) solutions after the electrochemical test were analyzed for Ni concentrations by inductively-coupled plasma mass spectrometry (ICPMS) and that data show that a much smaller amount of Ni has been released from the treated sample surface compared to the untreated control sample surface. Our results thus indicate that the deposited DLC film is effective in retarding the release of Ni ions from the bulk materials and more superior corrosion resistance is achieved based on our tests in a simulated fluid medium and at human body temperature.en_HK
dc.format.extent71207 bytes-
dc.format.extent17145 bytes-
dc.format.extent4339 bytes-
dc.format.mimetypeapplication/pdf-
dc.format.mimetypeapplication/pdf-
dc.format.mimetypetext/plain-
dc.languageengen_HK
dc.publisherIEEE.en_HK
dc.relation.ispartofIEEE International Conference on Plasma Scienceen_HK
dc.rights©2004 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.en_HK
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License-
dc.titleImproved corrosion resistance of plasma carbon coated NiTi orthopedic materialsen_HK
dc.typeConference_Paperen_HK
dc.identifier.openurlhttp://library.hku.hk:4550/resserv?sid=HKU:IR&issn=0730-9244&volume=&spage=351&epage=&date=2004&atitle=Improved+corrosion+resistance+of+plasma+carbon+coated+NITi+orthopedic+materialsen_HK
dc.identifier.emailYeung, KWK:wkkyeung@hkucc.hku.hken_HK
dc.identifier.emailLu, WW:wwlu@hku.hken_HK
dc.identifier.emailCheung, KMC:cheungmc@hku.hken_HK
dc.identifier.authorityYeung, KWK=rp00309en_HK
dc.identifier.authorityLu, WW=rp00411en_HK
dc.identifier.authorityCheung, KMC=rp00387en_HK
dc.description.naturepublished_or_final_versionen_HK
dc.identifier.doi10.1109/PLASMA.2004.1340075en_HK
dc.identifier.scopuseid_2-s2.0-13244267168en_HK
dc.identifier.hkuros87292-
dc.identifier.spage351en_HK
dc.identifier.epage351en_HK
dc.publisher.placeUnited Statesen_HK
dc.identifier.scopusauthoridPoon, RWY=34572161800en_HK
dc.identifier.scopusauthoridLiu, XY=8603933800en_HK
dc.identifier.scopusauthoridChung, CY=8100842800en_HK
dc.identifier.scopusauthoridChu, PK=36040705700en_HK
dc.identifier.scopusauthoridYeung, KWK=13309584700en_HK
dc.identifier.scopusauthoridLu, WW=7404215221en_HK
dc.identifier.scopusauthoridCheung, KMC=7402406754en_HK

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